CHAPTER XII

FIELD-TRIALS IN 1903

The extended series of shop tests which had occupied a considerable portion of the late winter and early spring of 1903 had demonstrated the following facts: First, with the aerodrome mounted on the launching car, a propeller thrust of from 450 to 475 pounds could be maintained indefinitely by the engine, and even when the engine was delivering its full power to the propellers, the vibration was so small as to cause no apprehension that the wings and rudder would be made to vibrate sufficiently to produce undue strains in them. Second, with the aerodrome suspended from the ceiling by springs at the points at which the wings would be attached, the vibration produced by the engine developing it’s full power was even less than when the machine was mounted on the launching car and there was, consequently, even less cause for concern that the wings and rudder might be set in vibration when the machine was free in the air. Third, the engine could be depended upon to deliver something over 52 horse-power when the five cylinders were working properly, and even with one cylinder not working, but acting as a dead load against the others, approximately 35 horse-power could be developed, while with two cylinders not working at all, the three which were working would deliver about 25 horse-power. Therefore, even assuming that two of the five cylinders might become deranged during a flight, there should still be sufficient power to propel the machine. These tests, some of which had been witnessed by members of the Board of Ordnance and Fortification, clearly demonstrated that the time had arrived when it was safe to give the aerodrome a test in free flight. The machine itself together with all its appurtenances and much extra material for repairs in case of breakages, which previous experience had shown to be almost certain, was accordingly taken from the shop and placed on the house-boat preparatory to taking it down the river to the point opposite Widewater, Va., which had already been selected as the “experimental ground.”

Owing to the limited size of the shops it had been impossible to place the wings and rudder in their proper positions on the aerodrome and determine its balancing in a way similar to that practiced with the models. The approximate settings for the wings and rudder had, however, been determined by calculation from the data obtained in the test of the quarter-size model, so that it remained only to place the wings and a weight to represent the rudder actually on the machine in the large space of the house-boat (which, however, was not large enough to permit the rudder to be assembled along with the wings), and thus check the balancing previously determined by calculation. There were very [p256] few appurtenances which could be shifted in balancing the aerodrome, but the proper disposition of weight had been so accurately determined by calculation that the floats, which, as will be seen from the various photographs, were merely cylindrical tanks with pointed ends, and of a sufficient capacity to cause a displacement great enough to float the aerodrome when it came down into the water, proved sufficient ballast for shifting the center of gravity to its proper point. The flying weight of the aerodrome was 830 pounds,[47] including the weight of the writer, which was 125 pounds. The total area of the wings or supporting surfaces was 1040 square feet, or the ratio of supporting surface to weight was 1.25 square feet per pound, which is the same as .8 pound per square foot.

After the balancing of the large aerodrome had been completed on the house-boat, and everything else got in readiness as far as could be done before actually arriving at the point at which the test was to be made, the house-boat was towed down the river on July 14, 1903, and fastened to its mooring buoy, which had been placed in the middle of the river at a point practically opposite Widewater, Va., and approximately forty miles from Washington. See Coast-Survey Chart, Plate 85.

Sleeping quarters for the force of eight workmen and the regular soldier from the United States Army, who had been detailed as a special guard, had been provided on the boat, but owing to the lack of space it had been found impracticable to arrange proper cooking facilities on the boat, and it had been found necessary to arrange to transport the workmen to Chopawamsic Island, near Quantico, Va., for their meals. It had been planned to use the twenty-five-foot power launch for this purpose, but owing to the heavy storms which became quite frequent soon after the house-boat was taken down the river, it was found that the small launch was not sufficient, and it was necessary to employ a tug-boat and keep it stationed there at all times. This added very considerably to the expense of the experiments, as the hire of this one tug-boat very nearly equalled the pay-roll of the workmen, and while it was not expected that the stay down the river would be so greatly prolonged as afterwards proved the case it was felt certain that minor delays were sure to occur and the experiments would at the very least require several weeks.

Had it been possible to foresee the great delay which finally occurred before the large aerodrome was actually launched, and the great expense arising from the necessity of maintaining one or more expensive tug-boats constantly, it is very certain that an experimental station nearer Washington would have been selected, even though the nearer places on the river which were available were much less suitable, both on account of the river being much narrower and the traffic very much heavier. In fact, at the time that the house-boat was taken down the river on July 14, with the expectation that the experiments with the [p257] large aerodrome would certainly be concluded within four weeks, the expenses of the work, which had been met from the Hodgkins Fund of the Smithsonian Institution since the original allotment from the Board of Ordnance and Fortification was exhausted more than a year previously, had already made such heavy drafts on this fund that Mr. Langley was most reluctant to draw further on it, even to the extent which seemed necessary to meet the expenses of a month of “field-work.”

Before making the tests of the large aerodrome, it was intended to give the quarter-size model a preliminary trial to test the balancing which it was proposed to use on the large machine. For this test it was planned to employ the small launching apparatus mounted on top of the small house-boat, which had been used in the experiments with the steam-driven models Nos. 5 and 6 in 1899, and later with the quarter-size model in 1901. However, after arriving down the river, it was found that the small house-boat which had been anchored at Chopawamsic Island since the experiments in 1901 had deteriorated to such an extent that it was unsafe to take it out into the river. The launching apparatus for the model was, therefore, removed from it and placed on the turn-table of the large house-boat, alongside the launching track for the large machine. After completing this transfer of the model-launching apparatus everything was thought to be in readiness for a test of the quarter-size model, but upon making a shop test of the model to make sure that its engine was working properly, it was found impossible to get it to work at all. A few explosions could be obtained once in a while, but very irregularly. After spending considerable time in trying to locate the difficulty, it was found that the commutator which distributes the high-tension sparking current to the proper cylinder at the proper time was short-circuited. This commutator had been made of “insulating fibre” and had never caused any previous trouble. It was now found, however, that the very damp atmosphere which had been experienced during the preceding two weeks, when the fog for a large portion of the time was so heavy that objects at a short distance across the water could not be seen, had caused the moisture to penetrate the fibre and thus destroy its insulating qualities. After much trouble some vulcanite and mica were secured and a new commutator made to replace the fibre one, and, then, after some minor difficulties had been remedied, the engine for the model was got into good condition again. After getting satisfactory shop tests on the model aerodrome, and having everything in readiness for a flight, it was necessary to wait many days before the weather was calm enough for a test. However, on August 8 the weather quieted down and the model was launched at 9.30 a. m. into a wind blowing about 12 miles per hour from E. SE.

Referring to Plate 86, which shows the quarter-size model mounted on its launching car on top of the large house-boat, and which was taken only a few [p258] minutes before the model was actually launched, it will be noted that a board (‹A›) projects from the front of the launching car. This board, which is mounted in a false floor of the launching car, is so arranged that when it strikes the two blocks (‹B›) at the end of the track it is driven backward in the car against the triggers which prevent the uprights (‹D›), supporting the aerodrome, from being folded down against the floor. When this board strikes the triggers it releases them and the springs (‹C›), which in this case were rubber bands, immediately fold the vertical posts or uprights (‹D›) against the brace posts (‹E›), which are immediately folded down flat against the floor of the car through the action of the spring hinges, by which they are connected to it. These uprights (‹D›), which support the aerodrome at the front and rear, respectively, are not released until a fraction of a second after the release of the clutch hook (‹F›), which is attached to the middle upright (‹G›), and which, grasping the lower pyramid, holds the machine down firmly against the uprights (‹D›) previously referred to. In order to prevent the possibility of the aerodrome being released prematurely while the car is held at the extreme rear end of the track by the hook (‹H›), a steel pin (‹J›), which can just be seen in the photograph, is pushed through a hole in the board (‹A›), and into a hole in a cross-member on the bottom of the car, thus holding the board in its proper position. After the engine is started up one of the mechanics who has assisted in starting it is under orders to remove the pin at the word “Ready,” and at the word “Go” the other mechanic who has assisted in starting the engine is under orders to release the hook (‹H›), and thus allow the car to dash down the track. In the experiment on August 8 the mechanic failed to remove the pin (‹J›) at the proper time, and it was only after the machine had been released and started down the track that it was seen that the pin had not been removed. It was then, however, too late to stop it, so the car dashed down the track. Although the striking of the board against the blocks caused the pin to split the board to pieces, the launching apparatus worked perfectly and the aerodrome started off on a perfectly even keel, the propellers revolving at an exceedingly high rate of speed. The aerodrome flew straight ahead for a distance of 350 feet, when it began to circle towards the right, descending slightly as it circled. Upon completing a quarter circle it again began to rise, flying straight ahead until it had gone a similar distance, when it again lost headway, but before it reached the water the engine increased its speed and the aerodrome again rose. When the engine slowed down for the third time, however, the aerodrome was not many feet above the river, so that before the engine regained its normal speed the aerodrome touched the water with its propellers still revolving, but very slowly. While the total distance covered was only about 1000 feet, and the time that it was actually in the air 27 seconds, yet in this brief time it had served the main purpose for which it had been built, which was to find out if the balancing of [p259] the large aerodrome, which had been determined by calculation from the results obtained with the steam-driven models, was correct. For it was assumed that if the quarter-size model, which was an exact counterpart of the large machine, should fly successfully with the same balancing as that calculated for the large one, the large one could reasonably be expected to act similarly. It was at first thought best to make another test with the model immediately after recovering it from the water, but by the time it could be brought into the house-boat and the water which had got into the engine cylinders could be removed and the engine made to work properly quite a strong wind had sprung up and rendered further tests of the model on this day impossible. If the launching track for the small machine could have remained on the top of the boat without interfering with the completion of the preparations for testing the large machine, it would have been left there and other tests made with the model when the weather was suitable, but as this could not be done without interfering with the work on the large machine, and the delays with the model had already been so great, the small track was immediately removed and the model stored away in the house-boat for possible later tests.

At the first it was impossible to account for the engine on the model running so irregularly and slowing down so soon after it was launched, as it was felt very certain that the cylinders could not in so short a time, and with the aerodrome actually moving through the air, have heated up sufficiently to cause it. After a while, however, one of the workmen volunteered the information that in his zeal to fill the fuel tank completely so as to insure a long flight, he had caused the tank to overflow so that some of the gasoline had run into the intake pipe, and that he had noticed gasoline dripping from the intake pipe as the machine went down the track. This excess gasoline in the intake pipe had caused the mixing valve which controls the quality of the explosive mixture to be improperly set, so that it would not furnish the proper mixture when the fuel was supplied in the proper way by the carburetor, and consequently when this excess gasoline had evaporated, the mixture furnished to the engine was not proper, and it consequently slowed down, there being no human intelligence on board to correct the adjustment of the mixing valve.

A series of seven photographs of this flight of the quarter-size model is given in Plates 87 to 93. Plate 87, taken with a kodak from the tug-boat stationed several hundred yards directly ahead of the house-boat, shows the machine in full flight heading directly for the tug-boat. Although the aerodrome was about fifteen or twenty feet higher above the level of the water than the camera, still, at the considerable distance from which the photograph was taken, this view would not show so much of the under side unless the machine had been pointing upward. The photograph also proves very clearly that at the time it was taken the machine had certainly not dropped at all below the level [p260] at which was launched. In Plate 88 the camera was unfortunately not well aimed, and only the front guy-post, bearing points, float and bowsprit are visible, besides the blur of the propellers, which, it will be noted, were moving very rapidly. The camera with which this and the succeeding plates were taken was one of the two special telephoto cameras belonging to the Zoological Park, but built in the course of the aerodromic work and used where especially rapid shutters were needed. As the shutters on these cameras give an exposure of only 1/500 of a second, and consequently are sufficiently rapid to show the individual feathers in a rapidly moving bird’s wing, any distortion of the machine in flight would certainly have been shown, but, as will be seen from the later photographs, no distortion of any kind occurred, both the surfaces and the framework remaining in a perfectly straight condition. Near the bottom of Plate 88 is the tug from which Plate 87 was taken, and a careful inspection of Plate 87 shows two persons standing on the roof of the house-boat, below the upper works, the gentleman on the left being Mr. Thomas W. Smillie, the official photographer of the Smithsonian Institution, who took all of the photographs except Plate 87, and, as stated above, used therefor the special telephoto cameras with the rapid shutters. Plate 89 is an exceedingly good view, and shows the propellers revolving very rapidly while Plates 90, 91 and 92 show very clearly that the speed of the propellers had greatly decreased between the successive photographs. Plate 93 shows the aerodrome shortly after it touched the water and had been almost completely submerged, in spite of its floats, by the very strong tide which was running. Though these plates show all that photographs can, they give no adequate idea of the wonder and beauty of the machine when actually in flight. For while the graceful lines of the machine make it very attractive to the eye even when stationary, yet when it is actually in flight it seems veritably endowed with life and intelligence, and the spectacle holds the observer awed and breathless until the flight is ended. It seems hardly probable that anyone, no matter how skeptical beforehand, could witness a flight of one of the models and note the almost bird-like intelligence with which the automatic adjustments respond to varying conditions of the air without feeling that, in order to traverse at will the great aerial highway man no longer needs to wrest from nature some strange, mysterious secret, but only, by diligent practice with machines of this very type, to acquire an expertness in the management of the aerodrome not different in kind from that acquired by every expert bicyclist in the control of his bicycle.

In describing this flight immediately after it was made, Professor John M. Manly, who took the photograph shown in Plate 87, said: “The flight of the small aerodrome was an event which all who saw it will remember for the rest of their lives. We were, of course, in a state of considerable nervous excitement and tension, for, after weeks of delay from high winds, rains, and [p261] other uncontrollable causes, at last we had a day ideally suited to the test. This was, to be sure, not the great test, the final test, the test of the man-carrying flyer, but it was felt by all to be of almost equal importance, for if the balancing of the small aerodrome was correct, the large one would maintain its equilibrium, and the problem of human flight would be solved practically as well as theoretically. That the weather was now favorable for the test filled us with excitement. Again and again the favorable moment had seemed to come, and had gone again before we could make ready for it. The aerodrome was rapidly carried to the upper works of the house-boat and the observers and helpers went hastily to their positions. The large tug-boat was stationed directly ahead, almost in the line of flight, and about a mile from the house-boat. Signals of readiness were exchanged, and with every sense astrain we awaited the supreme moment. The rocket gave the starting signal, and instantly there rushed towards us, moving smoothly, without a quiver of its wings, with no visible means of motion and no apparent effort, but with tremendous speed, the strange new inhabitant of the air. Onward it moved, looking like a huge white moth, but seeming no creature of this world, not only on account of its size, its ease of movement and its wonderful speed, but also because of its strange, uncanny beauty. It seemed visibly and gloriously alive as it advanced, growing rapidly larger and more impressive. Straight at us it came, and for a moment there was a wild fear that it would come right on and crush itself against the ponderous tug-boat. There was a half impulse to move the tug-boat out of its way, but the aerodrome seemed to realize its danger and rapidly, though not abruptly or violently, as if it had intelligence and power of self-direction, it checked its speed and circled to the right, descending slightly. Soon it quickened its speed again and went straight ahead for about ten seconds, when it again checked its flight and descended, circling once more. Once again it attempted to increase its speed and rise, but it was too near the water, and in a few moments the waves had wet its propellers and wings, and it sank, a poor, bedraggled creature. But the vision of its beauty and power and seeming intelligence and life will long remain with those who saw its flight.”

After removing the model-launching track so that the final arrangements could be completed for testing the large machine, many weeks of delay were experienced, almost entirely due to the unusually bad weather conditions which prevailed, and which were unprecedented for the time of the year. However, on September 3 the weather became more suitable, and the aerodrome being in readiness the metal frame of the large machine was hoisted to the top of the boat and placed on the launching car, and the wings, rudder, etc., were then hoisted up and properly assembled and everything made ready for a flight. The parties with the telephoto cameras were sent to their stations on the shore, where definite base lines had been marked out so that with the data as to [p262] altitude and azimuth, which these cameras automatically recorded, the speed, height, etc., of the machine in flight could be accurately computed. After stationing the tug-boats at proper points, so as to render assistance should the aerodrome come down into the water at a considerable distance from the house-boat, it was found, upon attempting to start the engine, that for some reason it would not operate. The sparking battery which had been placed at the extreme rear of the aerodrome was found to be giving such a weak spark that it would not ignite the mixture in the cylinders. Upon removing the connection which grounded the terminal of the battery to the framework and replacing it by a large copper wire leading up to the engine so as to decrease the resistance of the circuit it was found that the battery still would not give sufficient spark. A large quantity of dry cells, such as were used for the engine, had been procured to insure against delay from lack of batteries, but upon attempting to get a new set from this reserve supply it was found that they, as well as the set that was on the machine, had so deteriorated that instead of giving eighteen amperes on short circuit they would give only three, which was not a sufficient current to enable the engine to operate. No shop tests on the large engine had been made since the large aerodrome had been brought down the river, as no provision had been made for properly supporting the aerodrome in the house-boat in such a way as to permit the large propellers to whirl around without causing damage, and, therefore, the batteries which had hitherto proved to be suitable had not had any special test since they had been brought down the river. As no batteries suitable for use were on hand, and as none could be procured from a point nearer than Washington, the test had to be abandoned for the day and the aerodrome removed to the interior of the boat.

It was at first impossible to account for the rapid deterioration of so large a number of dry cells, but it was later found that the damp, penetrating fogs which had been experienced for nearly two months were responsible for it, and that in order to preserve the batteries in such a climate it was necessary to place them in metallic boxes which could be nearly, if not quite, hermetically sealed. New batteries were immediately procured from Washington, and before again mounting the aerodrome on the launching track provision was made for testing the engine inside the house-boat.

Up to this time the wings had been stored inside the house-boat by suspending them from the ceiling, but the time required to hoist them to the upper works on top of the boat, after the main body of the aerodrome had been placed on the launching car preparatory to making a flight, had added so greatly to the delay, and consequently to the difficulty of getting the machine entirely ready for a flight while the weather conditions remained suitable for a test, that it was decided to build some framework on the upper works and cover it with canvas so as to provide some boxes in which the wings could be [p263] stored whenever it seemed probable that a flight would soon be possible. Some of the difficulties experienced in hoisting these wings from the interior of the boat to the upper works may be appreciated by an inspection of Plate 94, where one of them is seen just ready to be hoisted from the raft. Only one wing at a time could be handled on the raft, even when there was no appreciable wind or roughness of the water, so that in order to hoist all four wings the raft had to be hauled around from the door at the end of the boat to the side where the wing was hoisted, and back again four times every time the machine was assembled preparatory to a flight. The necessity for making occasional tests of the engine in order to make sure that no trouble would be again experienced in having proper batteries, etc., for the engine when the machine was again on the point of being launched also made it imperative to remove the wings from the interior of the house-boat, as the tremendous blasts of air from the propellers would certainly have wrecked the wings had they remained in the boat while the engine was being tested.

After the wings had been stored in the “wing boxes,” thorough tests of the engine were made, and before there came another day which was at all suitable for a trial, it was accidentally discovered that the glued joints in the cross-ribs of the large wings had been softened by the moisture of the fogs which had penetrated everything, and that the joints had all opened up and left the ribs in a practically useless condition.

It will be recalled from the description of these cross-ribs, Chapter VI, that the rib is composed of two channel-shaped strips, the edges of which are glued together while the strips are bent over a form which causes the ribs to maintain the curved form desired after the glue has hardened. Recalling these facts, it will be readily understood that there is at all times a considerable strain on the glued joints due to the two strips of wood trying to straighten out, and, therefore, if the glue should at any time become softened sufficiently to allow one strip to slide along on the other, the joint would open up and the rib would consequently become straight. When the construction of the hollow ribs was first contemplated it was realized that although the hollow construction would enable the ribs to be strong, and at the same time exceedingly light, yet it would make it imperative that the ribs be covered with a water-proof varnish in order to prevent the glue from being softened when the aerodrome came down into the water, as it was expected from the first that it would do at the end of its flight. Considerable time and attention had, therefore, been given to this very problem of securing a suitable water-proof varnish, and ribs coated with the varnish which was finally used had been submerged in water for more than 24 hours in testing this very point, and no softening of the glue could be detected after this long submergence. It had, therefore, been felt that the ribs had been given a test which was much more severe than any conditions which [p264] were likely to be met with, since the aerodrome would, in no case which could be anticipated, be in the water for so long a period as 24 hours, and no trouble from this source need be anticipated.

In the present case, however, the moisture of the atmosphere, which had been heavily laden with fog for several weeks, had penetrated the varnish and softened the glue, even though the submergence of 24 hours in water had shown no effect. To construct new ribs for the wings would have required several weeks, and the delays which had already been experienced had by this time prolonged the stay down the river so greatly that even under the very best conditions it seemed hardly possible to complete the tests before the coming of the equinoxial storms, which would make it necessary to remove the boat from the middle of the river and place it in a safe harbor. Something, therefore, had to be done, and that very quickly, so that an immediate test could be made, or else the tests would have to be delayed until the following season, or possibly postponed indefinitely on account of the lack of funds.

Owing to the varnish with which the ribs were covered, it was impossible in repairing them to carry out the first plan which suggested itself of binding the ribs with a strip of cloth impregnated with glue and wound spirally from end to end. As the wood was so very thin, it was impossible to bind the two parts together with wire, and even thin bands of metal driven up on the tapered portion of the rib were not likely to draw the two strips together without crushing the wood. What was finally done was to scrape the edges of the two strips where the joint had opened, thereby removing all the old glue, and after putting fresh glue on all these edges the two strips were drawn together and bound with surgeons’ tape, which was found to adhere very firmly even to the varnished surface.

After repairing the ribs in this manner and readjusting the guy-wires of their framework so as to make the wing assume the correct form, which had been slightly altered by the warping and twisting consequent on the opening up of the ribs, everything was again in readiness for a test in free flight, numerous tests of the engine having meanwhile been made both with the aerodrome frame inside of the house-boat and also when mounted on the launching track above. The weather, which had been unprecedentedly bad all summer, now became even worse, and although short periods of calm lasting an hour or less occasionally occurred, there were for several weeks no calm periods long enough for completing the necessary preparations and making a test, although the time required for assembling the aerodrome had been greatly shortened by building the “wing boxes” on the superstructure, and in other ways previously described. On several occasions when an attempt was made to utilize what appeared to be a relative calm, the aerodrome was assembled on the launching apparatus and everything got in readiness except the actual fastening of the [p265] wings and rudder to it, but in every instance, before the wings could be actually applied and a flight made, the wind became so strong as to absolutely prohibit a test. On two occasions when the wings were actually attached, heavy rain storms suddenly came up and drenched the machine before the wings could be removed, and on several occasions it was necessary to leave the entire metal frame and engine of the aerodrome mounted on top of the boat all night, because the heavy sea which was running made it impossible to utilize the large raft in returning the frame to the interior of the boat.

Finally, however, after it seemed almost useless to hope for calm weather, what appeared to be a most propitious day arrived on October 7. The wind which had been quite high in the early morning gradually quieted until at 10 a. m. it was blowing only about twelve miles per hour and the indications were that it would quiet down still more. Every energy was concentrated in getting the aerodrome ready at the earliest possible moment, as previous experience had shown too clearly that the conditions might be completely reversed in less than an hour. As the tide and wind caused the boat to swing up the river from its buoy, and thus made the launching track point down the river, the steam tug-boat was sent down the river for a distance of a mile or more so that, should the aerodrome come down into the water without being able to make a return trip to the house-boat, the tug-boat would be able to reach it quickly and render assistance to both the writer and the machine should they need it. At 12.20 p. m. everything was in readiness and what appeared to be the decisive moment had arrived, when the writer, after starting up the engine and gradually raising its speed to the maximum, and after taking the last survey of the whole machine to insure that everything was as it should be, finally gave the orders to release it.

Although the writer did not have the privilege of seeing it glide down the track, as his attention was too thoroughly engaged in insuring that he was in the proper position for reaching immediately any of the control apparatus, either of the aerodrome or of the engine, yet those who did witness the actual passage of the machine down the track have said that the sight was most impressive and majestic. No sign of jar was apparent when the machine was first released, but with lightning-like rapidity it gathered its speed as it rushed down the sixty feet of track, the end of which it reached in three seconds, at which time it had attained a speed of something over thirty-two feet per second. Just as the machine reached the end of the track the writer felt a sudden shock, immediately followed by an indescribable sensation of being free in the air, which had hardly been realized before the important fact was intuitively felt that the machine was plunging downward at a very sharp angle, and he instinctively grasped the wheel which controls the Pénaud tail and threw it to its uppermost extent in an attempt to depress the rear of the machine and [p266] thereby overcome the sharp angle of descent. Finding that the machine made no response to this extreme movement of the tail, he immediately realized that a crash into the water was unavoidable and braced himself for the shock. The tremendous crash of the front wings being completely demolished as they struck the water had hardly become apparent before he found himself and the machine plunging downward through the water. By some instinct he grasped the main guy-wires which were above his head, and pulling himself through the narrow space between them freed himself from the machine and swam upward as rapidly as possible. A few moments after reaching the surface of the water the uppermost point of the pyramid of the machine was seen to project from the water and he swam over and sat down on it until a row-boat could be sent to it from the nearby power-boat.

The first thing that the writer saw after looking around him was a newspaper reporter, his boatman expending the utmost limit of his power in pushing his boat ahead to be the first one to arrive.

After giving directions to the workmen regarding the recovery of the machine, the writer returned to the house-boat to obtain dry clothing, and although his first inclination was not to make any statement until a complete examination could be made to determine both the cause of the lack of success and also the extent of the damage which had been sustained by the machine, yet owing to the very great pressure brought to bear by the press representatives who said that unless some statement was given out they would write their own conclusions as to the cause of the mishap, he finally gave out the following statement:

STATEMENT MADE BY MR. MANLY TO ASSOCIATED PRESS

“It must be understood that the test to-day was entirely an experiment, and the first of its kind ever made. The experiment was unsuccessful. The balancing, upon which depends the success of a flight, was based upon the tests of the models and proved to be incorrect, but only an actual trial of the full-size machine itself could determine this. My confidence in the future success of the work is unchanged. I can give you no further information. I shall make a formal report to Secretary Langley.”

After recovering the machine the foreman of the workmen (Mr. Reed) [who together with Mr. McDonald were the only ones on top of the boat when the launching actually took place], busied himself to discover what had caused the jerk to the machine at the moment it was released, which had been immediately followed by the great depression of the front end. After some little time he discovered that the upright guide at the extreme front of the launching car (which, as heretofore stated, was slotted to receive a metal lug projecting from the end of the guy-post, and thus prevent the front end of the [p267] framework from being twisted by a side wind striking the machine while it was still on the launching car) had been distorted, the metal cap on it being stretched out of shape in a way which indicated that the pin of the front guy-post had hung in the cap, and that the guy-post was not therefore free from this part of the car when the end of the launching track dropped. The shock which the writer felt at the moment of launching and which had also been seen by others to occur was thus conclusively shown to have been due to the falling track, dragging the front end of the machine down with it. As the machine was travelling forward and the car had been almost instantly brought to a standstill by its buffer pistons co-acting with the buffer cylinders at the foot of the track, this front guy-post had been pulled backwards, and thus not only pulled the main guy-wires of the wings backwards and thereby depressed the front edge of the front wings so that they had no angle of inclination, but had also bent the front end of the metal framework downward,--effects which were discovered from the later examination of the frame and the guy-post itself. From the instantaneous photographs which were obtained, indisputable evidence was obtained that this was what actually occurred. Referring to the photograph, Plate 95, which was taken by Mr. G. H. Powell, Secretary of the Board of Ordnance and Fortification, and which shows the machine just a few feet in front of the point where it was actually launched, it will at once be seen that the front end of the frame is bent downward and that the front guy-post instead of being parallel with the rear one has been deflected backward at the lower end through an angle of 30 degrees. Referring further to the photograph, Plate 96, which was taken at the same instant as the one just described, it will be seen that even this one, which is a view of the machine as it passed almost directly over Mr. Smillie’s head, most clearly shows the extreme extent to which the front wings had been distorted, the rear edges of the wings near the frame having been twisted up until they struck the cross-frame, and the outer ends being free to twist had been forced up very much higher.

After completing the recovery of the machine and the examination as to the extent of the injuries it had sustained, and finding unquestionable evidence that the accident had been caused by the front guy-post hanging in its guide block on the launching car, the workmen were set to work straightening out and arranging the various parts, fittings and accessories, and cleaning up the engine which fortunately had sustained no injury whatever. After a consultation in Washington with Mr. Langley, who had been unable to be present at the experiment, both concerning what had already occurred and also what should be done regarding the future of the work, and in view of the fact that the statement which the writer had given to the press representatives, immediately after the accident, had been made before there had been time to make an examination of the machine itself, it was decided that it would be best to give to the press [p268] a short statement to correct the earlier one, and Mr. Langley accordingly made public the following note:

“Mr. Langley states that he was not an eye witness of the experiment at Widewater yesterday, having been detained in Washington by business, but that on the report of Mr. Manly, immediately in charge, he is able to say that the latter’s first impression that there had been defective balancing was corrected by a minuter examination, when the clutch, which held the aerodrome on the launching ways and which should have released it at the instant of the fall, was found to be injured.

“The machinery was working perfectly and giving every reason to anticipate a successful flight, when this accident (due wholly to the launching mechanism) drew the aerodrome abruptly downward at the moment of release and cast it into the water near the house-boat. The statement that the machine failed for lack of power to fly was wholly a mistaken one.

“The engine, the frame and all the more important parts were practically uninjured. The engine is actually in good working order. The damage done was confined to the slighter portions, like the canvas wings and propellers, and these can be readily replaced.

“The belief of those charged with the experiment in the ultimate successful working of the machine is in no way affected by this accident, which is one of the large chapter of accidents that beset the initial stages of experiments so novel as the present ones. It is chiefly unfortunate in coming at the end of the season when outdoor work of this sort is impossible.

“Whether the experiments will be continued this year or not has not yet been determined.”

In view of the many inaccurate accounts published in the daily press at the time of this experiment, special attention is directed to the fact that even under the enormous strain to which the aerodrome was subjected, due to its striking the water at an angle of approximately forty-five degrees and at a speed certainly not less than forty miles an hour, no bending or distortion of any kind was found in the frame after it was recovered, except that a slight depression at the front had been produced by the lower guy-post catching on the launching car, as previously described. This is very clearly seen in Plate 97, Fig. 1, which shows the aerodrome being hoisted from the water, and in Plate 97, Fig. 2, which shows it just afterwards resting on the raft, the wings, tail and rudder having been completely demolished by towing it through the water to the house-boat from the place where it struck the water. This single distortion, therefore, was in no way a result of the strains experienced by the frame either while it was in the air or when it struck the water. Some of the press reports, and, in fact, some of the accounts published in the scientific press, stated that the aerodrome frame had proved so weak that it broke while the machine was in the air, and that this was the cause of the accident. Nothing could be farther from the actual facts than this, for though there were many things connected with the machine which could not be properly tested until it was actually in the air, yet the strength of the frame had been most thoroughly [p269] tested in the shops prior to the trial, and it had been found that with the frame supported only at the extreme front and rear, no appreciable deflection was produced upon it by the concentrated weight of four men at the center, even when they simultaneously jumped up and down on it. That the aerodrome frame was amply strong was further evidenced by the fact that in the later trial, hereafter described, no injury was sustained by the frame even when the machine turned over in mid-air and struck the water flat on its back. In fact, no point regarding the aerodrome is more certain than that the frame was more than strong enough for its purpose.

Plates 98 to 100 show the aerodrome in the water from the moment after it arose and the writer, who had extricated himself while it was plunging down through the water and beat it to the surface, had swum over to it and sat down on the upper pyramid to await a row-boat, until the machine was taken in tow by the tug-boat.

As the weather conditions were continually growing worse, owing to the lateness of the season, it was decided that it would be absolutely impossible to undertake to keep the house-boat down the river until the aerodrome could be repaired and another test made, and the writer accordingly returned to Quantico on the following day, expecting to take the tug-boat from there to the house-boat and complete arrangements for bringing everything to Washington. On reaching Quantico, however, it was found that a most violent storm was raging on the river, and had, in fact, been increasing in violence since the evening of October 7, immediately following the trial. On account of the storm it was impossible to reach the house-boat or to get into communication with the workmen, who had sought refuge at the hotel at Clifton Beach, as the tug-boat itself was not at the point at which it was expected to be found, and, in fact, it had not been seen by any of the river people since the morning of October 8, when it was seen taking the workmen from the boat to Clifton Beach. Two days later, or October 11, when the storm had subsided and the tug-boat, which had been blown many miles down the river, was able to return the workmen to the house-boat, it was found that the storm had made a complete wreck of all the row-boats, the power-launch, and the large raft. The row-boats had been completely demolished on the beaches, the launch had been broken from its moorings to the house-boat and driven ashore some four miles down the river, where it was found with the deck torn completely off, a large hole stove in it amidships, and the engine seriously damaged, while the raft had been very seriously damaged on the beach many miles down the river. After making temporary repairs to the raft and getting it launched, it was used as a floating dock for making temporary repairs on the power-launch; both were then returned to their moorings at the house-boat and everything got in readiness for towing the house-boat to Washington, and this was finally accomplished on October 12. [p270] Even while the boat was en route some of the workmen were busily engaged in the repair of the damaged parts, the others having been sent ahead to Washington to begin work on the construction of new wings, so that another trial could be had at the earliest moment that the weather would permit.

One extra pair of wings was on hand, but these had been stored in the house-boat while it was down the river, and the damp weather, which had caused such serious damage to the cross-ribs of the wings which were actually used, had also so seriously affected the ribs of these extra wings that it was necessary to discard some of them and repair the others. An extra Pénaud tail was on hand, as well as a steering rudder, and it was estimated that unless some unforeseen delay occurred the aerodrome would be ready for flight in three weeks.

After making a careful examination of the places on the river which seemed most available for an experiment, it was finally decided to make the next test just off the Potomac Flats, at the junction of the main body of the river and the Eastern Branch, the traffic on this part of the river, which would have been more dangerous and troublesome during the summer, being quite light at this time of the year. By making the experiment at this point it was possible to leave the house-boat at its dock until the weather seemed suitable and then have a tug-boat tow it to the exact point, which would be determined by the state of the wind and the tide.

After more completely examining the condition of the framework of the machine, and discussing and maturely deliberating on the causes which had led to the accident of October 7, the writer advised Mr. Langley not to make any changes either in the machine itself or in the launching apparatus, except to remove the small lug from the metal rod which projected from the end of the guy-post, and which by catching in its guide on the launching car had been the sole cause of the accident. The aerodrome was accordingly repaired so as to reproduce exactly the conditions which obtained at the time of the previous experiment, except for this slight change, and it was again ready for trial by the middle of November. The weather, however, at this time was very variable, there being at times comparatively quiet periods which lasted for only an hour or less, which was not sufficient time for procuring a tug-boat and towing the boat to the proper point, and then assembling the aerodrome and making a trial. However, after many days waiting, what appeared to be an exceptionally quiet day occurred on December 8, the wind quieting down by noon to such an extent that practically a dead calm prevailed. Vigorous search was immediately instituted for a tug-boat to tow the house-boat to the point selected, but it was very late in the afternoon before one could be procured, and by the time the boat arrived at the proper place darkness was descending and a strong [p271] and exceedingly gusty wind had sprung up, and it seemed almost disastrous to attempt an experiment.

However, the funds which had been appropriated by the Board of Ordnance and Fortification had been exhausted nearly two years before, and all the expense since that time had been met from a special fund of the Smithsonian Institution. But, owing to the heavy drains which the work had made upon this fund, Mr. Langley felt unwilling to draw further upon it, and since there were no other funds available from which to meet the expenses which would be incurred by postponing the experiments until spring, it was decided that it was practically a case of “now or never,” and although the river was full of large blocks of floating ice several inches thick, which added enormously to the danger involved in the experiment, the writer decided to make the test immediately so that the long-hoped-for success, which seemed so certain, could be finally achieved.

After considerable delay, due to the great difficulty of properly assembling the huge wings in the strong and gusty wind, into which the boat could not be kept directly pointed, owing both to the strong tide which was running and to the fact that the wind itself was rapidly varying through as great a range as ninety degrees, and after many minor delays, due to causes too numerous to mention, the aerodrome was finally ready for test.

The wind was exceedingly gusty, varying in velocity from twelve to eighteen miles per hour and shifting its direction most abruptly and disconcertingly, so that the aerodrome was at one moment pointed directly into it and at the next moment side gusts striking under the port or starboard wings would wrench the frame severely, thus tending to twist the whole machine from its fastenings on the launching car. After starting up the engine and bringing it to full speed, the writer gave the signal for the machine to be released, and it started quietly, but at a rapidly accelerated pace, down the launching track. Exactly what happened, either just before or just as the aerodrome reached the end of the track, it has been impossible to determine, as all the workmen and visitors had gone to their stations on the various auxiliary boats, except the two workmen (Mr. Reed and Mr. McDonald) who had been retained on top of the boat to assist in the launching. It had grown so dark that the cameras of Mr. Smillie, the official photographer, were unable to get any impression when he used them, owing to the extreme rapidity of the shutters with which they were equipped. Fortunately, one photograph of the machine while still in the air was secured, which shows the result of what had occurred in the launching and before any further damage had been caused by its coming down into the water, but the all-important question as to just what caused the accident which did occur remains to a certain extent a mystery. [p272]

Mr. Reed, the foreman, who was qualified to observe accurately, not only through his having worked continuously for many years on the machines, but also from his having witnessed the numerous tests of the models, states that from his position near the rear end of the launching track he noticed that at a point about ten feet before the machine reached the end of the track the Pénaud tail seemed to have dropped at the rear end in some inexplicable way so that it was dragging against the cross-pieces of the track, and that at the next instant, when the car reached the end of the track, he saw the machine continue onward, but the rudder and whole rear portion of the frame and the wings seemed to be dragging on the launching car. Mr. McDonald, the head machinist, states that he had his attention so concentrated on the engine, which he noticed was working perfectly and driving the propellers at a higher rate of speed than he had ever before seen it do, that he did not see anything happen until he saw the machine shoot upward in the air, gradually attaining a vertical position with its bow upward, where it was sustained for a few moments by the upward thrust of the propellers. After a few moments, however, the strong wind, which was blowing from twelve to eighteen miles an hour directly ahead and acting against the wings which were now vertical, drove the machine backwards towards the house-boat, and he saw it come down into the water on its back, with the writer gradually righting himself in accordance with the turning of the machine until he was finally hidden from view by the machine coming down on top of him. The witnesses on the tug-boats seem not to have been able to perceive exactly what occurred. All unite in stating that something seemed to happen to the machine just a few feet before the launching car reached the end of the track, but what it was they could not say. Everyone who saw the accident and who was sufficiently familiar with the construction of the machine to be able intuitively to form an idea as to just what was taking place was so very close to the machine that when the accident happened everything seemed to merge into one vision, which was that of the whole rear of the wings and rudder being completely destroyed as the machine shot upward at a rapidly increasing angle until it reached the vertical position previously mentioned.

The writer can only say that from his position in the front end of the machine, where he was facing forward and where his main attention was directed towards insuring that the engine was performing at its best, he was unable to see anything that occurred at the rear of the machine, but that just before the machine was freed from the launching car he felt an extreme swaying motion immediately followed by a tremendous jerk which caused the machine to quiver all over, and almost instantly he found the machine dashing ahead with its bow rising at a very rapid rate, and that he, therefore, swung the wheel which controls the Pénaud tail to its extreme downward limit of motion. Finding that [p273] this had absolutely no effect, and that by this time the machine had passed its vertical position and was beginning to fall backwards, he swung himself around on his arms, from which he supported himself, so that in striking the water with the machine on top of him he would strike feet foremost. The next few moments were for him most intense, for he found himself under the water with the machine on top of him, and with his cork-lined canvas jacket so caught in the fittings of the framework that he could not dive downward, while the floor of the aviator’s car, which was pressing against his head, prevented him from coming upward. His one thought was that if he was to get out alive he would have to do so immediately, as the pressure of the water on his lungs was beginning to make itself seriously felt. Exerting all of the strength he could muster, he succeeded in ripping the jacket entirely in two and thus freeing himself from the fastenings which had accidentally held him, he dived under the machine and swam under the water for some distance until he thought he was out from under the machine. Upon rising to the surface his head came in contact with a block of ice, which necessitated another dive to get free of the ice. Upon coming to the surface of the water he noticed Mr. Hewitt, one of the workmen, just about to plunge in; before he could call out to indicate he was safe, Mr. Hewitt had heroically plunged in with the expectation of diving under the machine where he believed the writer to be entangled. Finding the house-boat was being rapidly shoved upon him, imperilling the life of both himself and Mr. Hewitt, besides the safety of the aerodrome, the writer gave orders that the tug-boat reverse and tow the house-boat away. Then, with the assistance of a row-boat, he reached the house-boat, where willing hands drew him on board and assisted him into dryer and warmer clothing.

Meanwhile, it had become quite dark, and when the writer went outside to see about the aerodrome he found that the men on the tug-boat, in their zeal to render assistance, had fastened a rope to the rear end of the machine, at the same time pulling it in the direction in which the front end was pointed, and through their ignorance had forced it down into the muddy bottom of the river and broken the main framework completely in two, thus rendering it absolutely impossible with the facilities at hand to remove it from the water to the interior of the boat. It was finally necessary to tie the wrecked machine to the stern of the house-boat and have the boat towed to its dock where the mast and boom were assembled and the wrecked machine hoisted from the water. This was finally accomplished about midnight, when the workmen, who had been working at a fever heat all day, were glad to close up the work for the day, which had proved so unfortunate.

As has already been remarked, darkness had descended to such an extent that the light was not strong enough to give photographs with the very rapid shutters with which Mr. Smillie had his cameras equipped, and that, therefore, [p274] incontrovertible evidence, which the instantaneous photographs had given as to just what had occurred to the machine in the accident of October 7, was in this case unfortunately lacking. It was at first thought that no photographs had been obtained while the machine was actually in the air, but it was later found that by some rare fortune the photographer for ‹The Washington Star› had secured a photograph, which, while small, showed very distinctly some decidedly interesting facts. An enlargement of this photograph is shown in Plate 101, by the kind permission of ‹The Washington Star›. Referring to this photograph, it will be seen that at the moment it was taken the machine was practically vertical in the air, and it confirms the testimony of the eye witnesses, and also the writer’s impression that the machine was maintained in a vertical position for several moments by the upward thrust of the propellers. It will also be seen that the Pénaud tail has been completely demolished and is hanging as a limp roll of cloth, which the strong wind has deflected backwards towards the house-boat, the port rear wing has broken its main ribs, both where they are attached to the main frame and also about midway the length of the wing, the outer end being partially folded towards the frame. The starboard rear wing has also broken both of its main ribs at the point where they are joined to the frame, and they have also broken at a point about one-third their length from the frame, the outer end being likewise folded towards the frame. By a still more careful inspection, it will also be seen that the port front wing is apparently uninjured, while the starboard front wing has broken the middle main rib at a point between the sixth and seventh cross-ribs, and while it cannot be distinctly seen at first that the front main rib has also broken at the same point very careful inspection will show that this is the case, as the sixth and seventh ribs, showing as faintly darker lines in the photograph, are seen to be displaced, so that they are together and actually crossing each other. It will furthermore be seen that both front wings have been pressed upward by the wind until their tips near the inner ends are in contact with the cross-frame. This could not have happened unless the front guy-post had given away either by bending or breaking. The fact that it has given way is further evidenced by a more careful examination of the extreme front end of the machine, where it will be seen that the bowsprit and the curved tubes which form the extreme end of the steel frame have been bent from a straight line with reference to the main frame. This bending of the bowsprit and the curved tubes could be produced only by the front guy-post coming in contact with some obstruction on the launching car as the machine left it. It is known very certainly that the rear end of the machine came in contact with the launching car, as the car itself shows a very deep gash in the wooden cross-piece at its center, which was produced by the port-bearing point at the rear striking it. As this bearing point was elevated five feet above the cross-piece of the launching car, and was also six feet six inches to [p275] the rear of the point where the wood is torn, this rear-bearing point must have travelled downward at an angle of approximately thirty-eight degrees in order for the bearing point to strike the car at this point. As the lower end of the rear guy-post was only eighteen inches above the cross-piece of the launching car, it, of course, would be broken before the bearing point could descend so much. As has been previously stated, Mr. Reed, who was at the rear of the launching track, states very positively that the rudder was dragging on the track at least ten feet before the launching car reached the front end of the track where the machine was actually launched. There are several ways in which the rudder could have gotten down on the track, but positive information is lacking. If it was dragging on the track, as Mr. Reed states (and from his extended experience and rather acute powers of observation I should place great credence in his report), the subsequent demolition of the guy-posts succeeded by the destruction of the rear wings and serious injury of the front ones is easily explained. If the dropping of the rudder on the track occurred from the breaking of the upper rudder post, over which the upper control wire passed, the lower vertical surface would first come in contact with the track, and the destruction of this part would certainly occasion subsequent destruction of the horizontal and upper vertical surfaces of the rudder, leaving the central rib of the rudder still attached to the frame, and upon the machine being released from the car a few moments later this destroyed rudder would easily catch in the launching car and pull the aerodrome down on it, and thus cause the destruction of the guy-posts, wings, and so forth. If the dropping of the rudder was caused primarily by its main rib breaking loose from its connection with the frame, the rudder would still be dragged along behind the machine by the wire cords through which it was operated, and the subsequent launching of the machine would still give the rudder every chance to catch in the launching car and drag the machine down on it.

It can therefore be said that, while positive information is lacking, there is very strong evidence that the accident in the launching was due to the rudder becoming entangled with the launching track owing to the breakage of some part of the mechanism by which it was connected to the main frame.

It is of importance to note that the photograph furnishes incontrovertible evidence that the main frame of the machine was in no way injured, except for the slight bending of the forward curved extension, and that, therefore, the accident was in no way due to the weakness of the frame. The main frame was not even injured by the machine coming down in the water on its back, and the later damage was entirely caused by the combination of the ignorance of the tug-boatmen and the darkness in which they were working, when they attempted to tow it to the rear of the house-boat so that it could be removed from the water. [p276]

On the day following the trial a very careful inspection was made in the hope of obtaining some more definite information as to just what caused the accident, but the serious injury to the machine caused by the tug-boatmen breaking it in the water had so greatly tangled things up that it was impossible to tell anything about it. The workmen were immediately put to work removing fittings from the broken wings, rudder, etc., and dismounting the engine, which was immediately reassembled on its testing frame and found to be absolutely uninjured. The transverse frame of the machine was comparatively uninjured, the damage done by the men on the tug-boat being the breaking of the machine in two at a point just back of the cross-frame, together with the consequent destruction of the bearing points, “trestle,” and certain fittings by which the main guy-wires were attached to the main tubes and pyramids.

The situation which now existed was most distressing and disheartening. Mr. Langley felt that he could not approve of further expenditures from any Smithsonian fund, and the Board of Ordnance and Fortification of the War Department having been severely criticised on the floors of Congress for its original allotment for the work, deemed it inexpedient to incur a possible curtailment of the funds annually placed at its disposal for general experimental work through a manifestation of continued interest in the flying machine.

As has already been stated, representatives from the Board of Ordnance and Fortification of the War Department were present at both tests of the large aerodrome; on October 7 Major Montgomery M. Macomb and Mr. G. H. Powell, and on December 7 General W. F. Randolph accompanied by Major Macomb and Mr. Powell, represented the War Department, and Dr. F. S. Nash, at that time Contract Surgeon, U. S. A., was officially present at both trials to render medical assistance should it be needed.

By permission of the War Department, the official report of the tests submitted by Major Macomb to the Board of Ordnance and Fortification is here made public:

Enc. 1st to 3d end’t, BOF 6191.

REPORT

Experiments with working models which were concluded August 8 last having proved the principles and calculations on which the design of the Langley aerodrome was based to be correct, the next step was to apply these principles to the construction of a machine of sufficient size and power to permit the carrying of a man, who could control the motive power and guide its flight, thus pointing the way to attaining the final goal of producing a machine capable of such extensive and precise aerial flight, under normal atmospheric conditions, as to prove of military or commercial utility.

Mr. C. M. Manly, working under Prof. Langley, had, by the summer of 1903, succeeded in completing an engine-driven machine which under favorable [p277] atmospheric conditions was expected to carry a man for any time up to half an hour, and to be capable of having its flight directed and controlled by him.

The supporting surface of the wings was ample, and experiment showed the engine capable of supplying more than the necessary motive power.

Owing to the necessity of lightness, the weight of the various elements had to be kept at a minimum, and the factor of safety in construction was therefore exceedingly small, so that the machine as a whole was delicate and frail and incapable of sustaining any unusual strain. This defect was to be corrected in later models by utilizing data gathered in future experiments under varied conditions.

One of the most remarkable results attained was the production of a gasoline engine furnishing over fifty continuous horse-power for a weight of one hundred and twenty pounds.

The aerodrome, as completed and prepared for test, is briefly described by Prof. Langley as “built of steel, weighing complete about seven hundred and thirty pounds, supported by one thousand and forty feet of sustaining surface, having two propellers driven by a gas engine developing continuously over fifty brake horse-power.”

The appearance of the machine prepared for flight was exceedingly light and graceful, giving an impression to all observers of being capable of successful flight.

On October 7 last everything was in readiness, and I witnessed the attempted trial on that day at Widewater, Va., on the Potomac. The engine worked well and the machine was launched at about 12.15 p. m. The trial was unsuccessful because the front guy-post caught in its support on the launching car and was not released in time to give free flight, as was intended, but on the contrary, caused the front of the machine to be dragged downward, bending the guy-post and making the machine plunge into the water about 50 yards in front of the house-boat. The machine was subsequently recovered and brought back to the house-boat. The engine was uninjured and the frame only slightly damaged, but the four wings and rudder were practically destroyed by the first plunge and subsequent towing back to the house-boat. This accident necessitated the removal of the house-boat to Washington for the more convenient repair of damages.

On December 8 last, between 4 and 5 p. m., another attempt at a trial was made, this time at the junction of the Anacostia with the Potomac, just below Washington Barracks.

On this occasion General Randolph and myself represented the Board of Ordnance and Fortification. The launching car was released at 4.45 p. m., being pointed up the Anacostia towards the Navy Yard. My position was on the tug Bartholdi about 150 feet from and at right angles to the direction of proposed flight. The car was set in motion and the propellers revolved rapidly, the engine working perfectly, but there was something wrong with the launching. The rear guy-post seemed to drag, bringing the rudder down on the launching ways, and a crashing, rending sound, followed by the collapse of the rear wings, showed that the machine had been wrecked in the launching, just how, it was impossible for me to see. The fact remains that the rear wings and rudder were wrecked before the machine was free of the ways. Their collapse deprived the machine of its support in the rear, and it consequently reared up in front under the action of the motor, assumed a vertical position, and then toppled over to the rear, falling into the water a few feet in front of the boat. [p278]

Mr. Manly was pulled out of the wreck uninjured and the wrecked machine was subsequently placed upon the house-boat, and the whole brought back to Washington.

From what has been said it will be seen that these unfortunate accidents have prevented any test of the apparatus in free flight, and the claim that an engine-driven, man-carrying aerodrome has been constructed lacks the proof which actual flight alone can give.

Having reached the present stage of advancement in its development, it would seem highly desirable, before laying down the investigation, to obtain conclusive proof of the possibility of free flight, not only because there are excellent reasons to hope for success, but because it marks the end of a definite step toward the attainment of the final goal.

Just what further procedure is necessary to secure successful flight with the large aerodrome has not yet been decided upon. Professor Langley is understood to have this subject under advisement, and will doubtless inform the Board of his final conclusions as soon as practicable.

In the meantime, to avoid any possible misunderstanding, it should be stated that even after a successful test of the present great aerodrome, designed to carry a man, we are still far from the ultimate goal, and it would seem as if years of constant work and study by experts, together with the expenditure of thousands of dollars, would still be necessary before we can hope to produce an apparatus of practical utility on these lines.

M. M. MACOMB, Major Artillery Corps.

WASHINGTON, January 6, 1904.

The attitude of the Board of Ordnance and Fortification, with reference to rendering further financial assistance to the work, is clearly shown by the following extract from the official report of the Board on October 6, 1904, to the Secretary of War:

THE LANGLEY AERODROME

Early in the year 1898 a board composed of officers of the Army and Navy was appointed to examine the models and principles of the aerodrome devised by Dr. S. P. Langley, Secretary of the Smithsonian Institution, and to report whether or not, in its opinion, a large machine of this design could be built, and, if so, whether it would be of practical value.

The report of this board was referred to the Board of Ordnance and Fortification for action, and Doctor Langley was invited to appear before the Board and further explain the proposed construction.

In view of the great utility of such a device, if a practical success, the Board, on November 9, 1898, made an allotment of $25,000 for the construction, development, and test of an aerodrome to be made under the direction of Doctor Langley, with the understanding that an additional allotment of the same amount would be made later. On December 18, 1899, the additional allotment of $25,000 was made.

The construction of the machine was delayed by Doctor Langley’s inability to procure a suitable motor, which he was finally obliged to design. The aerodrome was completed about July 15, 1903, and preparations for its test were made at a point in the Potomac River about 40 miles below Washington. [p279]

Preliminary arrangements having been completed and tests made of a quarter-size model, the first attempt at actual flight with the man-carrying aerodrome was made on October 7, 1903.

On this occasion there were present on behalf of the Board, Major M. M. Macomb, Artillery Corps, and Mr. G. H. Powell, clerk of the Board.

Major Macomb in his report to the Board stated that--

“The trial was unsuccessful because the front guy-post caught in its support on the launching car and was not released in time to give free flight, as was intended, but on the contrary, caused the front of the machine to be dragged downward, bending the guy-post and making the machine plunge into the water about 50 yards in front of the house-boat.”

This accident necessitated the removal of the house-boat to Washington for the more convenient repair of damages. The repairs having been completed, on December 8, 1903, another attempt at a trial was made, this time at the junction of the Anacostia and the Potomac Rivers. General W. F. Randolph and Major Macomb, members of the Board, and Mr. Powell, were present. Major Macomb reported as follows:

“The launching car was released at 4.45 p. m. . . . The car was set in motion and the propellers revolved rapidly, the engine working perfectly, but there was something wrong with the launching. The rear guy-post seemed to drag, bringing the rudder down on the launching ways, and a crashing, rending sound, followed by the collapse of the rear wings, showed that the machine had been wrecked in the launching, just how, it was impossible for me to see.”

March 3, 1904, the Board stated that it was not “prepared to make an additional allotment at this time for continuing the work,” whereupon Doctor Langley requested that arrangements be made for a distribution of the aerodrome material procured jointly from funds allotted by the Board and by the Smithsonian Institution. Doctor Langley was informed that all of the material would be left in his possession and available for any future work that he might be able to carry on in connection with the problem of mechanical flight.

That this refusal of the Board of Ordnance and Fortification to render further assistance to the work was due to the fear that such action would result in a curtailment of their appropriation by Congress is clearly shown by the following extract from the official report of the Board on November 14, 1908, to the Secretary of War:

AERIAL NAVIGATION

For a number of years the Board has been interested in the subject of aerial navigation, and as long ago as 1898 made allotments to carry on experiments with a machine of the heavier-than-air type, under the direction of the late Dr. S. P. Langley, Secretary of the Smithsonian Institution, who had made exhaustive experiments in aerodynamics,[48] and who had demonstrated the practicability of mechanical flight by the successful operation of engine-driven models.

The many problems and mechanical difficulties met with in the development of the full-size machine have been set forth in the various published statements[49] [p280] of Doctor Langley, and the unsuccessful outcome of the experiments is too well known to require reiteration. It may be said, however, that at the time of the trials the Board was of the opinion that the failure of the aerodrome to successfully operate was in no manner due to the machine itself, but solely to accidents in the launching apparatus, which caused the wreck of the aerodrome before it was in free flight.

Doctor Langley considered it desirable to continue the experiments, but the Board deemed it advisable, largely in view of the adverse opinions expressed in Congress and elsewhere, to suspend operations in this direction.

These adverse opinions expressed in Congress were wholly due to the bitter criticism by the newspapers, whose hostility was engendered by Mr. Langley’s refusal to admit their representatives to the shops and house-boat where the work was in progress. Mr. Langley had at all times tried to make his position in the matter clear to the newspapers, but, on August 19, 1903, at the time of one of his visits to the experimental station near Widewater, Va., he found the newspaper representatives so persistent in their misrepresentations of his reasons for excluding them that he gave out the following statement, which was published at that time:

SMITHSONIAN INSTITUTION, WASHINGTON, D. C., August 19, 1903.

TO THE PRESS: The present experiments being made in mechanical flight have been carried on partly with funds provided by the Board of Ordnance and Fortification and partly from private sources, and from a special endowment of the Smithsonian Institution. The experiments are carried on with the approval of the Board of Regents of the Smithsonian Institution.

The public’s interest in them may lead to an unfounded expectation as to their immediate results, without an explanation which is here briefly given.

These trials, with some already conducted with steam-driven flying machines, are believed to be the first in the history of invention where bodies, far heavier than the air itself, have been sustained in the air for more than a few seconds by purely mechanical means.

In my previous trials, success has only been reached after initial failures, which alone have taught the way to it, and I know no reason why the prospective trials should be an exception.

It is possible, rather than probable, that it may be otherwise now, but judging them from the light of past experience, it is to be regretted that the enforced publicity which has been given to these initial experiments, which are essentially experiments and nothing else, may lead to quite unfounded expectations.

It is the practice of all scientific men, indeed of all prudent men, not to make public the results of their work till these are certain. This consideration, and not any desire to withhold from the public matters in which the public is interested, has dictated the policy thus far pursued here. The fullest publicity, consistent with the national interest (since these recent experiments have for their object the development of a machine for war purposes), will be given to this work when it reaches a stage which warrants publication.

(Signed.) S. P. LANGLEY.

Although it was impossible to immediately find funds for actively continuing the work, the writer finally, after some delay, persuaded Mr. Langley to allot a small sum from a limited fund which personal friends had some time previously placed at his disposal for use in any experiments he might wish to make. This small sum was used to meet the expense of the workmen who were kept employed long enough to completely repair the main frame so that, should further experiments be possible at a later time, there would be no danger of important parts and fittings having been lost in the meantime, and even if no further experiments were made the frame would be in such condition that others could profit from an examination of it, the frame itself embodying the solution of many important problems which had cost much time and money.

In the spring of 1904, after the repairs to the main frame were well under way, the writer on his own initiative undertook to see what could be done towards securing for Mr. Langley’s disposal the small financial assistance necessary to continue the work; but he found that while a number of men of means were willing to assist in the development of the aerodrome, provided arrangements were made for later commercialization, yet none were ready to render the assistance from a desire to assist in the prosecution of scientific work. Many years prior to this Mr. Langley had had some very tempting propositions made to him by certain business men with a view to carrying on the work in a way that would lead to later commercial development. He had never patented anything previously in his life, and although many friends had urged that it was only proper that he should patent whatever of value had been developed in connection with the aerodromes, he steadfastly refused to do so. He had given his time and his best labors to the world without hope of remuneration, and he could not bring himself at his stage of life to consent to capitalize his scientific work. Success seemed only a step away, and his age was such that any delay in achieving success increased the probability of his not living to see it, but he maintained positively and resolutely that, if neither the War Department nor others felt sufficient interest in the work to provide the small amount of funds necessary to continue the experiments, and they therefore could be continued only by his giving in and permitting his work to be capitalized, he would have to deny himself the hope of living to see the machine achieve success.

The result is well known to all.

PRESENT STATUS OF THE WORK

The completely repaired frame of the large machine is now stored in one of the workshops at the Smithsonian Institution. The large engine, the steam-driven models Nos. 5 and 6, and the quarter-size model, driven by the three [p282] horse-power gasoline engine, are on exhibition at the U. S. National Museum. The launching-car and a small amount of materials have also been stored away. The large house-boat, the construction and maintenance of which proved such a serious drain on the finances, and the preservation of which would have entailed the continuance of heavy fixed charges, has been turned over to the War Department and sold, as has also the power-launch and other paraphernalia which it seemed useless to preserve.

The writer is firmly convinced that the aerodrome is not only correct in principle but that it possesses no inherent faults or weaknesses, and that the success which the work deserves has been frustrated by two most unfortunate accidents in the launching of the machine. Other plans of launching, several of which were studied out during the early stages of the work on the large machine, would have avoided the accident which did occur, but, of course, might have produced others possibly even more disastrous, but which could be determined only by actual trial. But even recognizing certain fundamental weaknesses of the launching mechanism as used, he believes that there is no inherent reason why the machine should not have been successfully launched, and that the accidents which proved so disastrous in the two experiments were not such as should cause a lack of confidence in the final success of the aerodrome.

It might be of interest to add that the writer is now preparing to resume the work at the earliest opportunity, and that the machine will be used in practically the form in which it existed at the two previous experiments, though a slight change will be made permitting experiments over the land rather than the water. The only thing that prevents an immediate resumption is the pressure of private business matters.

Before closing this record the writer wishes to acknowledge the very valuable assistance in the work rendered by Mr. Richard Rathbun, Assistant Secretary of the Smithsonian Institution, through his moral support and interest in it at all times, and especially during the trying days of the summer of 1903; by Captain I. N. Lewis, who, while Recorder of the Board of Ordnance and Fortification from 1898 to 1902, manifested keen interest in the work and gave it his moral support before the Board; by Professor John M. Manly, who devoted the whole of the summer of 1903 to it; and by Professor W. G. Manly, who devoted a large part of the summer of 1903 to assistance in the preparation for the actual field-trials of the aerodrome.

Mention must also be made of the very loyal and valuable services rendered by Mr. R. L. Reed, the very efficient foreman of the work during the last ten years of its progress, to whom much credit is due for his perseverance and skill in overcoming many of the difficulties which presented themselves, as well as to Mr. G. D. McDonald, Mr. C. H. Darcey, Mr. F. Hewitt, Mr. R. S. Newham [p283] and the other employees who labored faithfully for the several years they were engaged on it.

BLÉRIOT MACHINE OF 1907 ON LANGLEY TYPE

Since completing the preparation of this Memoir, the writer’s attention has been called to some very interesting tests made at Issy by M. Louis Blériot with a machine of the Langley type. These tests confirm in such a practical manner the conviction that the large aerodrome would have flown successfully had it not been wrecked in launching that it has seemed well to here quote an interesting description of them published in the “Bollettino della Società Aeronautica Italiana, August, 1907,” under the title “Il nuovo aeroplano Blériot,” a translation of which is as follows:

THE NEW BLÉRIOT AEROPLANE

The Blériot IV in the form of a bird, of which we spoke at length in No. 4 of the Bulletin of this year, does not appear to give good results, perhaps on account of its lack of stability, and Blériot instead of trying some modifications which might remedy such a grave fault, laid it aside and at once began the construction of a new type, No. V, adopting purely and simply the arrangement of the American, Langley, which offers a good stability (see Bulletin 11–12, November to December, 1905, pages 187 and 188).

The experiments, which were commenced a month ago, were first completely negative, because the 24 HP. motor would not turn the propeller, which was 1.80 m. in diameter and 1.40 m. pitch.

By advice of Captain Ferber, Blériot reduced the pitch of his propeller to 0.90 m., so that the motor could give all its force.

This modification was an important one for his aeroplane. From that moment every trial marked an advance. On July 12, he made a flight of 30 m., and the aviator was able to show that the lateral stability was perfect. On July 15, the trial was made against a wind of 6 miles an hour, but gave good results. He made a flight of 80 m., showing, however, that the hind part of the aeroplane was too heavy. In this flight he arose as high as a second story, and on landing the wheels and one propeller were somewhat damaged.

On July 24, repairs having been completed, a new trial was made. This time, in order to remedy the defect in the balance, Blériot had moved his seat forward about 80 cm. The correction was too great, for on that day the aeroplane, although the hind part arose, was not able to leave the ground. On July 27, after having mounted the seat on wheels as skiffs, Blériot resumed the trials and made a flight of 120 m., at first moving his seat back and then, after getting started, bringing it forward. Blériot had not provided this aeroplane with an elevating rudder, but, following the example of Lilienthal, changed the center of gravity of the apparatus by moving his own person, and after having established the proper angle remained immovable on his seat. In order to arise or descend, the aviator made use of the spark lever, thus varying the number of turns of the propeller.

During a second trial on the same day, having accidently reached the limit of the aviation field, Blériot, without allowing himself to be surprised and obliged to descend, decided to attempt a turn by maneuvering the steering rudder [p284] and to return again to the center of the field. With marvelous precision, the aeroplane began to describe a circle of about 200 m. radius, inclining as if on a banked track. Having finished the flight, he quickly regained his balance still in the direction of the wind, but on account of a slight movement of the aviator, the aeroplane fell to such an extent that he was obliged to land. He landed gently and without shock, rolling on his wheels.

On August 1, he made another flight of 100 m. in 6-1/2 seconds; and on the 6th, one of 265 m. with one interruption. While the attention of the pilot was distracted for a moment, the aeroplane, which was flying at a height of 2 or 3 m. above the ground, touched the soil with its sustaining wheels at the end of 122 m. and then immediately arising, covered the remaining 143 m. at a height of 12 m. Blériot, moving forward too quickly, caused the aeroplane to descend swiftly to the ground, and the shock broke the axle and the blades of the propeller were bent. In order to confirm this account, we reproduce what was said in the “Auto” of August 7, 1907.

“M. Blériot, continuing the trials of his aeroplane yesterday, surpassed the superb results which he had already obtained. The trial took place at 2 o’clock in the afternoon on the aviation field of Issy. After a sustained flight of about 122 m. at a height of 2 m., the aeroplane touched the ground, without stopping, however, and set out again almost immediately at a height of 12 m. and traversed about 143 m. M. Blériot, who for the time had no other means of balancing but by moving his body, then moved a little forward to stop the ascent. The aeroplane plunged forward, and in the fall the propeller was damaged and the axle broken.

“M. Blériot, whose courage as a sportsman equals his learning as an engineer, was fortunately uninjured. An inspection of the apparatus showed that one blade of the propeller was bent, which was sufficient to prevent the maneuver made by the aviator having its desired effect and contributed to the fall. The engine will be repaired without difficulty and the trials will be resumed Friday.”

On August 10, he made a flight of 80 m., but the motor was not in perfect order, so Blériot did not make other trials. He decided, however, to substitute definitely a 50 HP. motor for the 24 HP. motor with which he made all the experiments above reported, which were of a character to encourage the most sanguine expectations.

Ferber advised Blériot to adopt an elevating rudder also, because the effect produced by changing the position of the center of gravity, although efficacious is very difficult and delicate to control.

The conclusion of an article by Ferber in “Nature” of August 10, is worthy of note. He says: “Let us remark, in conclusion, how fruitful is the method of personal trial which we have always advised in preference to any calculation. This year, with his fourth apparatus, Blériot has not met with any damage to his aeroplane. He made the trials himself and they quickly led to results, because each trial gave him an exact idea of what was to be corrected. That is the condition of success.”

[p285]

APPENDIX STUDY OF THE AMERICAN BUZZARD AND THE “JOHN CROW”

In the preparation of this Memoir, the writer has deemed it best to generally omit any mention of plans and ideas which were brought forth in the work, unless constructions or tests in accordance with them were carried to a sufficient extent to admit of some definite conclusion regarding them. However, owing to the important part played by the warping of the supporting surfaces, or the variation in the angle of auxiliary surfaces, in the methods of preserving the equilibrium of practically all flying machines of the present day, it may be of interest to here add a short mention of the direction in which plans along this line were originally proposed in this work. Mention has already been made of the importance which Mr. Langley attached to the study of the works of the great master-builder, Nature, though recognizing at the same time that owing both to the difference in the forces and methods of construction possible to man, it was not in general possible for him to produce the best results by attempting to too closely imitate the methods or plans of Nature.

Mr. Langley considered it not practicable or best to attempt to imitate the details of construction of the flying mechanism of birds. At the same time, he strongly believed that much was to be learned from them about the practical side of the art of balancing, and he therefore spent a great deal of time both in analyzing the methods practiced by the birds in preserving their equilibrium and in criticizing his own plans in this direction in the light of what Nature would seem likely to do if she had to construct a flying creature on such a large scale. In carrying on his investigations in the art as practiced by the birds, he made a trip to Jamaica during the early weeks of 1900, in order to study the species of buzzard which are so numerous and tame there and are known locally as the “John Crow.” After his return from this trip he wrote the following very interesting letter to Mr. Robert Ridgway, requesting certain data regarding the American buzzard, which he wished to compare with some data on the “John Crow” which he had obtained on this trip:

MARCH 29, 1900. DEAR MR. RIDGWAY:

I have just returned from Jamaica, where among other occupations, I have been studying the evolutions of the buzzard locally called the “John Crow,” a soaring bird which is almost as much superior in skill to our buzzard as that is to a barn-yard fowl in its power of keeping itself in the air without flapping its wings, in what is very nearly a calm.

I have observed particularly the following points with the Jamaica specimen (which I can only give, however, approximately), and I should like to have you give corresponding ones for our Washington buzzard if you can oblige me. [p286]

I note here that the measurements were made on a live bird and that it was impracticable to get the separate weight of the wings except by estimate, but the two wings may be estimated collectively as 1-1/4 lbs., the whole weight being 2-3/4 lbs. to 3 lbs.

Approximate values:

Weight of the bird complete, 3 pounds. Length of bird, 23 inches. Spread of wings from tip to tip, 5 ft. 5 in.

Complete curtate area of both wings (that is, the area of the shadow of the bird’s wings when these are fully extended under a vertical sun) is 600 square inches, or nearly 4 sq. ft., consequently each square foot of the bird’s sustaining surface carries 3/4 lbs. Diedral angle nearly 150°.

When the bird is soaring in a nearly calm atmosphere, which it inexplicably does,--soaring I mean nearly in line of the observer’s eyes and coming directly to of going directly away from him,--it presents nearly the following appearance:

FIGS. 1 and 2.--Type sketches of wings by Holmes from a mean of positions taken from his own sketches and photographs, and also from sketches and photographs by Langley.

[p287]

I must preface what follows by a little statement of the things which particularly interest me here and which are not a naturalist’s ordinary concern.

First, I want to know the ‹CG› of the bird when in flight. You will understand that though there is but one center of gravity (here symbolized as ‹CG›), it may be considered (1) with reference to its position on the horizontal plan of the bird with wings extended, when it will always be found somewhere in the medial vertical plane, passing through the body, and usually nearly at a certain point with reference to length, the position thus considered being called ‹CG›, or (2) the position of the same ‹CG› with reference to a vertical plane passing transversely through the medial line, the position thus considered being called ‹CG›_2. In the latter case you will understand that the ‹CG› which is that of the whole body, wings and all, will be carried more or less upward when the wings are thrown high up, and will be carried temporarily downward when the wings are at their lowest point of the stroke. It would have a certain position when the bird was at rest and another position when it was soaring and the wings were above the body.

The soaring bird is chiefly held upward by the pressure of the air under each wing, and just as the common center of gravity is a point where all the efforts of gravity are supposed to be centered, so there is a common center of pressure, or one point where all the efforts of the upper pressure of the air may be supposed to be centered, and it will be clear, on very little consideration that this latter point must be always nearly in a vertical line through the ‹CG›, and usually above it. Call it ‹CP›.

‹CG›_1 and ‹CP›_1 are then, the symbols of ‹CG› and ‹CP› as referred to the horizontal plane. ‹CG›_2 and ‹CP›_2 are the symbols for the corresponding ones when referred to their position in the vertical plane.

I shall be glad to explain to you, if you are not familiar with it, the simple method of finding the ‹CG›_1 and ‹CG›_2. It consists in bending the wings into just the position that they would ordinarily occupy above the body in plain soaring flight, keeping them there by a very light bent stick or wire, then hanging the bird up by a line attached to the tip of one wing, and see where this line would pass through the body of the bird, for the ‹CG› will be somewhere in this line. After marking then, on the body of the bird its position, hang it up a second time by the head or tail and note again where the new vertical line runs in the new position. There is but one ‹CG› and but one point in which two straight lines can cross, and that will be the ‹CG› necessarily. Note with all care just where this is above or below the center of the body of the bird.

As for the ‹CP› for either wing, that may be nearly found by tracing the wing on a flat piece of thick paper or cardboard strong enough not to bend much--cutting out the tracing and balancing it well on the point of a pencil--the point about which it balances is very near ‹CP›_2 or the center of pressure in the vertical plane. There is such a point of course in each wing, and when they are thrown up in the actual position that they have in calm soaring flight, we may suppose a horizontal line drawn between them, and it is the distance from this horizontal line to ‹CG›_2 compared with the area of the wings or with the distance between their extended tips which we want to know, which gives the vertical distance which the ‹CG› is below the ‹CP›, the thing we want to know.

It will be very convenient also to have a wing dissected from the body and the wing itself held in about the soaring curve by a bit of light stick balanced on a pencil point, which will give the ‹CG› of the wing as distinct from that of the body. However, the three things I principally want, beside a sketch or [p288] photograph of the bird from about its own level coming directly toward or going directly away in soaring flight, are these:

Approximate weight of the bird,--and approximate tracing of its extended wing with the area, so that we can tell the area of the supporting surface relative to the weight, and finally, the distance between ‹CP›_2, and ‹CG›_2, which is obtainable by the process which I have explained.

I am afraid that what I have just been describing at such length may have a certain obscurity to you, but if you will give me an opportunity, I shall be pleased to illustrate it with the actual experiment when the bird is hung up by a string, and you will see that it is in reality simple.

Referring to the sketches on page 3 of this communication, ‹a› and ‹b› correspond to the centers of pressure on either wing where the upward pressure of the air distributed over each wing may be supposed to be gathered in a single point. This, as I have said, is called the center of pressure with reference to the vertical flight, and its symbol is ‹CP›_2, while the horizontal dotted line between them represents the level of ‹CP›_2, from the best estimate that I could make when the wings are in their natural position of soaring. It is evident that this line passed far above the body of the vulture, and if (the corresponding symbol for the height of the center of gravity being ‹CG›_2), the ‹CG›_2, of the entire bird be taken, it will be found to lie nearly in the point ‹c›. Where ‹c› is in the present case, I could not determine exactly in my hasty examinations in the live bird, but I assume that it is about 1/2 way between the central horizontal axial line of the bird’s body and the upper portion. I repeat that it is important to me to know what the vertical distance is between ‹CP›_2 and ‹CG›_2 in each specimen of soaring bird. I may observe in illustration that in the common sea-gull, it is nearly as shown in the faint sketch; that is to say, that the corresponding line ‹a› ‹b› in the soaring gull passes distinctly through the upper part of the body, and the distance down to the ‹CG›_2 of the whole in the gull is almost nil, while in the buzzard it is very considerable as shown by the corresponding distance in the “John Crow.”

Now, what I want to get from you is the corresponding figures for an average specimen of our Washington buzzard. If you will kindly have one killed and weighed while fresh, and before the rigor-mortis has set in, first noting the position of its wings when soaring in a calm, and (if possible) when coming toward you or going away in about a horizontal plane with your eye, in which position the wings will be elevated and bent somewhat as in the case of the above sketch of the “John Crow”; if you will kindly do this, so as to give me corresponding facts with reference to the buzzard, namely weight, area of extended wing surface, distance between tips as bent up in ordinary flight, distance between ‹extended› tips, ‹the quantity› ‹CP›_2−‹CG›_2, and also will make such a tracing of the buzzard’s wing as Mr. Manly will show you of the “John Crow’s,” I shall be obliged.

My impression is that the buzzard is a considerably heavier bird than the “John Crow,” without, however, very much greater spread of wing. I may observe that when the wings of the Jamaica bird were spread out, they were spread quite to their utmost extent, and the distance between the tips of the terminal feathers was much greater than when in flight. I wish you would kindly also add the scientific name of the “John Crow,” with any particulars that you would think of interest.

If there be any special expenses incurred in the preparation of this memorandum, including the time of a photographer, I will direct them to be paid from the Smithsonian fund. [p289]

If you could get Mr. Holmes (who made most of the sketches and all of the photographs of the “John Crow”), to try and do something like this for your buzzard, especially getting such a photograph of it ‹in flight›, as will give the position of its center of gravity relative to the center of pressure on the wings, it would add very greatly to the value of your memoranda, and I think Mr. Holmes takes so full and intelligent an interest in the subject, that he might be pleased to give his help.

Very truly yours, S. P. LANGLEY, ‹Secretary›.

MR. ROBERT RIDGWAY, Smithsonian Institution, Curator, Division of Ornithology, U. S. National Museum, Washington, D. C.

In response to this request, Mr. Ridgway submitted the following very interesting information:

SMITHSONIAN INSTITUTION, UNITED STATES NATIONAL MUSEUM

WASHINGTON, D. C., October 16, 1900.

PROF. S. P. LANGLEY, Secretary, Smithsonian Institution.

SIR:

I have the honor of submitting herewith the data obtained by Mr. Rolla P. Currie concerning measurements, etc., of the common Turkey Buzzard (‹Cathartes aura›) of the United States, as requested by you in your letter of March 29, last.

The difficulties in the way of securing these data, already explained by me in previous communications, are responsible for the delay in submitting them.

Hoping that this material may prove of use to you, I am,

Very respectfully, R. RIDGWAY, ‹Curator, Division of Birds›.

MEMORANDA IN REGARD TO THE TURKEY BUZZARD (SECOND SPECIMEN)

1. ‹Weight›.--1850 grammes.

2. ‹Area of outstretched wings›.--641 square inches. (Computed from three sheets of tracings, ‹A›_1 and ‹A›_2 comprising the entire area of both wings; ‹B›, a single wing.)

‹Note›.--As the bird was in process of moult, one of the large wing quills, as shown by the tracings and compo-board patterns, is but partially developed, thus slightly modifying the results obtained. Its length, if full grown, would be nearly the same as that of the quill just above it.

3. ‹Distance between the tips of these wings›.--5 feet, 8.7 inches.

4. ‹Distance between the tips of the same wings when the bird is in horizontal soaring flight›.--Estimating the dihedral angle of the wings to be 150°, and elevating the wings so as to make this angle, the distance between their tips [p290] measures 5 feet, 5.7 inches, or 3 inches less than when fully extended in the horizontal plane.

5. ‹The position of the center of pressure of the wing›.--This is indicated on two compo-board patterns, ‹C› and ‹D›. ‹C› was made from a fully extended wing, while ‹D› was made from the wing in the soaring position. The centers of pressure of the wings are about 2 feet, 0.5 inches apart, or 1 foot, 0.25 inches from the central point of the bird’s body.

6. ‹The position of the center of gravity of the soaring bird›.--(Length of buzzard, 26 inches.) The center of gravity of the soaring buzzard in the horizontal plane, CG_1, was found to lie 9-1/2 inches behind the tip of the beak and 16-1/2 inches in front of the tip of the tail.

The center of gravity of the soaring bird in the vertical plane, ‹CG›_2, was found to lie 2.8 inches above the ventral point of the body and 1.6 inches below the dorsal point, the depth of the bird’s body at ‹CG›_1, being 4.4 inches.

In determining the center of gravity, the bird was frozen in the soaring position, its wings making a dihedral angle of 150°. It was then hung up, first horizontally and then vertically, and balanced till the line from which it was suspended coincided with a plumb-line placed in front of it; the measurements were then made.

The bird was afterwards, and while still frozen, hung up in the same way in Mr. Smillie’s photographic room, and exposures made by him in both positions. These photographs, ‹E›_1 and ‹F›_1 were enlarged to natural size, and measurements made on the enlargements yielded, as nearly as could be determined, the same results as when taken directly upon the bird.

As determined by measurements upon the buzzard in soaring position, the center of gravity was found to be 2.65 inches below the center of pressure (estimating the center of pressure to be at the bend of the wing); or, employing the compo-board pattern in a corresponding position, the distance was seen to be a small fraction of an inch less.

7. ‹The position of the root of the wing›.--This is indicated on the tracing A_1.

‹a.› (Depth of the body on a vertical line with root, 3.5 inches.) The root lies 1.6 inches below dorsal line, 1.9 inches above ventral line.

‹b.› (Length of body, 26 inches.) The root lies 7.6 inches behind tip of beak, 18.4 inches in front of tip of tail.

8. ‹The dihedral angle between the wings›.--The photographs taken previously were not sufficiently large or distinct to enable us to determine this with exactness. It was estimated, however, as 150°, and experiments were made on this basis.

9. ‹The center of gravity of the dissected wing›.--This was found, ‹first›, for the wing having all the muscles, up to the ball and socket joint, intact. One of the wings was frozen in the soaring position and its center of gravity found by balancing on a point. Its position was marked by a wire thrust through the wing at this place, and the wing (‹H›) is preserved in formalin. This position is also marked on a special tracing, ‹I›. It lies 6 inches from the base of the humerus bone (root of wing). ‹Secondly›, it was found for the wing denuded of all muscle. Its position was marked on the other wing of the bird, which is preserved dry, spread in the soaring position. It lies 9-3/4 inches from the base of the humerus. [p291]

10. ‹The weight of the dissected wing›.--

‹a.› With all muscle up to the ball and socket joint intact, 325 grammes.

‹b.› With all muscle removed, 190 grammes.

Weight of muscle, therefore, 135 grammes.

‹The position of the root of the tail›.--

‹a.› In the horizontal plane, 11.8 inches in front of the tip of the longest tail feather; 14.2 inches behind tip of beak.

‹b.› In the vertical plane: (depth of body from ventral point below root of tail to a point directly above, which is on a level with the highest point of the back, 2.5 inches.) 1.5 inches above ventral point, 1 inch below dorsal point.

‹Weight of tail›.--With muscle, 40 grammes; ‹without› muscle, 30 grammes. Weight of muscle, therefore, 10 grammes.

EXHIBITS ACCOMPANYING THESE MEMORANDA

‹A›_1 and ‹A›_2. Two sheets, comprising a tracing of the entire turkey buzzard with fully outstretched wings. From these the area of the wings and the distance between their tips was obtained. The position of the root of the wing and the root of the tail is also marked on one of these sheets.

‹B.› One sheet, comprising a tracing of a single wing, and from which the area was also computed. This area, multiplied by 2, gives the same result as the sum of both wings on A_1 and A_2. The compo-board pattern ‹C› was made from this tracing.

‹C.› Compo-board pattern of fully extended wing, on which the center of pressure is indicated.

‹D.› Compo-board pattern of wing in soaring position, on which the center of pressure is shown. [p292]

‹E›_1. Photograph of bird in soaring position, suspended horizontally.

‹E›_2. Same, enlarged to natural size.

‹F›_1. Photograph of bird in soaring position, suspended vertically.

‹F›_2. Same, enlarged to natural size.

‹G.› Tracing of wing in soaring position, from which the compo-board pattern ‹D› was made.

‹H.› Wing preserved in formalin, on which the center of gravity is recorded.

‹I.› Tracing of wing ‹H› when frozen in soaring position, on which the center of gravity is marked.

‹J.› Wing with muscle removed, on which the center of gravity is shown.

Several persons connected with the Smithsonian Institution and U. S. National Museum have contributed towards securing the results herewith submitted. Among them, I desire especially to mention Mr. W. H. Holmes, Mr. [p293] F. A. Lucas, Mr. N. R. Wood, and Mr. R. L. Reed. Mr. Holmes superintended the experiments in connection with ‹No. 6› (finding the bird’s center of gravity), and by his suggestions and criticisms helped me in many other particulars. The photographs and enlargements were made by Mr. T. W. Smillie.

Respectfully submitted, ROLLA P. CURRIE, ‹Aid, Division of Insects, acting in the Division of Birds›.

OCTOBER 16, 1900.

The feats of airmanship performed by the “John Crow” seemed to greatly impress Mr. Langley and shortly after this trip he wrote the following letter to the writer:

SMITHSONIAN INSTITUTION WASHINGTON, D. C., April 16, 1900.

DEAR MR. MANLY:

I am reminded of the consequence that I have, in connection with Mr. Chanute and perhaps Mr. Huffaker, attached in the past to the possibility of directing the bird, and consequently the flying machine, by the mere inflection of the wing, that is, by changing its angle; and you recall to me that Mr. Huffaker at one time proposed to arrange a wing, with some provision of a spring, which should enable it to change its angle automatically. . . . .

I have been noting this ability to guide by the slight inflection of the wing, in my studies of the Jamaica buzzard, and am ready to say that I think, while the quarter-sized working model of the great aerodrome is building, it will be worth while to make some arrangement of the frame or wing-holder which will make it possible to test this idea. I will endeavor to work out something of the kind more in detail myself, but whatever it is, it will apparently involve the ability of the wing to rotate about a line passing nearly through it lengthwise, and an allowance for this; if not in the wing itself, then in the wing-holder; will need to be made while the present model is under construction.

I will request you to especially look out for this, as far as you can on these indications.

Very respectfully yours, S. P. LANGLEY, ‹Secretary›.

The instructions and suggestions contained in this letter and in many conferences on the subject were never carried out by the writer, on account of the extreme pressure of the work already on him which had for its object, not the production of a flying machine which would embody all of the control which we wished it to have, but which would be burdened only with such devices and arrangements as would enable it to transport a human being, and thus demonstrate the practicability of human flight.

[p294]

SECRETARY LANGLEY’S INSTRUCTIONS TO ASSISTANTS

SMITHSONIAN INSTITUTION, WASHINGTON, D. C., November 30, 1895.

DEAR SIR:

The following instructions are to replace those of May 13, 1895:

1. The ‹minimum› fraction of its own “flying weight” (that is, weight complete with initial water and fuel), which the aerodrome shall lift on the pendulum, is 50 percent,[50] under such engine power as can certainly be gotten up in the field and maintained during forty seconds from the time the aerodrome is let go.

The blast, the pumps, and all other essential parts must, in other words, be in such a condition that steam enough for this lifting over 50 per cent of weight can be gotten up readily and surely in the field and in a time which will still leave at least forty seconds’ supply.

2. The ‹minimum› relation of supporting area to weight in any aerodrome constructed hereafter, is to be two feet to the pound,[50] and the minimum of power at the rate of one steadily-maintained horse power[50] at the brake under ordinary conditions, to not over twenty-two pounds (ten kilos) of flying weight. In absence of a brake determination horse power may be taken--

H. P. = (revs. per min. at rest × pitch × diameter (in ft.) × thrust (in lbs.)) / 33,000.

These rules do not apply to No. 5, but they do to No. 6, which is to be built over, if necessary, to meet them.

3. In balancing an aerodrome, unless otherwise instructed, set wings at a root angle of either 10°, 7°, or 5°, after being certain from previous inversion and sanding, that the tip angle in motion will not differ from this root angle as much as 5°.

The object in balancing any aerodrome with a single pair of wings is to be able to bring the ‹c g›_2 under their ‹c p›_2 without any reference to the tail, which supports nothing, unless specially ordered. But as this condition cannot now be obtained in Nos. 5 and 6, these at any rate, and perhaps future aerodromes, are to carry a second pair of wings. When this second pair of wings is of nearly equal size with the first it is to be assumed in preliminary adjustments for weight and center of pressure, that the second pair has two-thirds the lifting efficiency per unit area of the first.

Calling the whole distance from the mean center of pressure of the wings to the center of gravity ‹M›. ‹M› is to have a definite relation to the breadth of [p295] wings from tip to tip (‹b›) and total fore and aft length (1), which is provisionally fixed at M = √(bl)/8, and the line of thrust is to be not over one-fourth the way from ‹c p›_2 to ‹c g›_2.

Generally speaking the front pair of wings will be fixed in position and the adjustment for balancing made by moving the rear pair.

The individual weights of all parts checked by lump weighing are to be given by the caretaker (Mr. Huffaker), under the general scheme shown in the note. The work on the aerodromes being divided into two classes, viz.: metal work and all which is not metal, the two in charge of this work (Mr. Reed and Mr. Maltby) are severally responsible for knowing the weight in grammes of any of the parts they have put into their work, giving these weights to Mr. Huffaker, together with any data for filling out the annexed tables,[51] on his request.

Until further orders, Mr. Huffaker is charged with the responsibility of seeing that these conditions are met before any aerodrome is boxed, and will keep the record of weights of the aerodromes and their principal parts as already completed, in a book, to be preserved in your keeping, which will also be arranged to show with signed ‹photographs› and descriptions, and with sketches where needed, the condition and weight (as far as constructed) of every aerodrome, and of any new construction of any part, on the first of each month.

Particular attention is directed to the preceding paragraph, and to the need that evidence of a definite character is to be obtained and preserved of everything already done, and being done.

Without special orders to the contrary, you will not authorize the boxing of any aerodrome which does not, to your knowledge, meet these conditions.

Each aerodrome is to have the following parts in duplicate or in triplicate:

2 pairs wings; 2 pairs tails; 2 pairs light silk covered rudders; 3 pairs wheels;

with any other parts in duplicate or triplicate, which experience has shown to be necessary.

Mr. Reed will not box any aerodrome till a certificate from Mr. Huffaker can be put on the inside cover, with the list of contents, showing what the conditions are as to weight, wing area, power, etc., and the person in the field charged with the duty of launching the aerodrome (at present Mr. Reed), is authorized not to let it go unless he is satisfied that it has a full forty seconds’ supply of steam. [p296]

I am satisfied that a great deal of time is lost in putting the aerodrome together for flight, owing to the absence of any preliminary drill in doing this. Before it goes into the field the whole is to be completely boxed, and then taken out from the box and set up on the clutch, and steam gotten up for flight. All this is to be done in the shop before the final boxing, and provision is to be made so that no wiring or adjusting of parts is to be done in the field which can possibly be avoided by forethought in the shop. The tail-piece, for instance, is to be bushed with brass, so that it will always come into the same place, and make a tight fit, in spite of wetting or shrinking, in the steel tube, where it is to go into a guide-way with a bayonet spring, or a like contrivance for setting it at once securely into position.

The mean positions of the wings and tail are to be laid out in some way permanently on the mid-rod, but every guy-rod or adjustable piece is to be arranged so as to fit at once securely and permanently in its position without wiring or like slow process.

Very truly yours, S. P. LANGLEY, ‹Secretary›.

W. C. WINLOCK, Esq., Assistant in Charge, Smithsonian Institution.

A copy to be communicated to:— Mr. Huffaker, Mr. Reed, Mr. Maltby.

FOOTNOTES.

[37] “The Flying Machine” ‹McClure’s Magazine›, June, 1897.

[38] One noted astronomer and mathematician re-affirmed this opinion as late as 1900 and even stated that man could not hope to construct a flying machine capable of sustaining a weight as great as our largest birds, knowing that even at that time the model Aerodromes Nos. 5 and 6 had already done more than this.

[39] These wings are described in Chapter VI, pp. 191.

[40] See “Experiments in Aerodynamics.” It will be recalled that in the experiments with the “plane-dropper” there was a greatly reduced lifting power with superposed planes when their distance apart was one-half the width the planes, unless a speed of about 42.5 feet a second was obtained. In the above tests with the superposed wings, the speed was only from twenty to twenty-two feet a second at the time of launching, and as the distance between the surfaces was only one-half as great as their width, it is not surprising that the lifting power should not be as great as with the “single-tier” wings.

[41] In fact the setting of the tail at a negative angle and fastening it to the frame by an elastic or spring connection was only begun in 1896, and while it proved to be the key to the solution of the problem of automatic longitudinal stability, yet it was not at that time so recognized, although the first real test of the aerodromes after the elastic connection and negative angle of the tail were adopted resulted in the epoch-making flight of No. 5 on May 6. By comparing the angle of the tail on No. 5 in Plate 27A, Part I, with the angle of the tail on No. 6 in Plate 27B, Part I, it will be seen that while the first had an angle of much less than 5 degrees, the latter had an angle of about 15 degrees. But the wooden springs changed so that it was not accurately known what the angle really was at the time at either flight in 1896.

[42] The drawings, Plate 55, which illustrate many of the fittings used on the frame, show the guy-wires as attached by means of loops twisted in their ends, these drawings having been made before the final plan of attaching the wires had been devised.

[43] See explanation of system of locating points in Part I, Chap. II, p. 15.

[44] See Balancing of Engines, by Archibald Sharpe.

[45] Except for a ten minute stop to renew the supply of lubricating oil and change the sparking batteries.

[46] See foot-note, page 249.

[47] The weight was afterwards increased to 850 pounds due to repairing the wings and adding more sparking batteries.

[48] See Experiments in Aerodynamics, Smithsonian Contributions to Knowledge, Vol. 27, Washington 1891.

[49] Researches and Experiments in Aerial Navigation, Smithsonian Publication No. 1809, Washington, 1908.

[50] All these minimum permissible conditions are connected by the tacit assumption that the supporting area is not greatly over 2 ft. to the pound of weight. If for instance the weight were increased by larger wings or more wings, furnishing a much greater supporting area per pound, these conditions would not necessarily apply.

[51] These tables were later designated as “Data Sheets.” Several copies, with the data duly entered on them, are given in this appendix, and the form which Mr. Langley included in this letter is therefore not repeated here.--EDITOR.

[p297]

DATA SHEETS.

DATA SHEET No. 1.

Weight of Aerodrome No. 5, as photographed on May 11, 1896. Certified to by R. L. Reed, May 6, 1896.

---------------------------------------+----------+-------------+ Parts. | Sizes. | Weight. | ---------------------------------------+----+-----+------+------+ |‹m.›|‹ft.›|‹gr.› |‹lbs.›| 1 Frame, including everything of | | | | | metal, permanent and undetachable, | | | | | such as bed-plate, cross-rods for the | | | | | support of propellers, bearing points | | | | | for clutch, etc. | | | 2443| | | | | | | 2 Engine, gears, shafts, etc. | | | 1110| | | | | | | 3 Pump, pump shaft | | | 231| | | | | | | 4 Hull covering | | | 350| | | | | | | 5 Gasoline tanks, valves | | | 178| | | | | | | 6 Smokestack | | | 342| | | | | | | 7 Float | | | 275| | | | | | | 8 Reel | | | 77| | | | | | | 9 Wing clamps, 235; clamp for | | | | | guy-posts, 29 | | | 264| | | | | | | 10 Other things, counter | | | 75| | | | | | | 11 Burners | | | 360| | | | | | | 12 Boilers | | | 651| | | | | | | 13 Separators, steam gauge, pipe to | | | | | engine | | | 540| | | | | | | 14 Exhaust pipe | | | 143| | | | | | | 15 | | | | | | | | | | 16 | | | | | | | | | | 17 Wings (without clamp) | | | 1950| | | | | | | 18 Tail (without clamp) | | | | | | | | | | 19 Rudder | | | 350| | | | | | | 20 Guy sticks, each, 57 | | | 114| | | | | | | 21 Propellers | | | 800| | | | | | | 22 Extra length of midrod, 308; drop | | | | | piece for rudder, 40 | | | 348| | | | | | | 23 Wood Bowsprit | | | 74| | | | | | | 24 Other things | | | | | | | | | | 25 | | | | | | | | | | 26 | | | | | | | | | | 27 Fuel (at starting flight) | | | 200| | | | | | | 28 Water (at starting flight) | | | 900| | | | | | | 29 | | | | | | | | | | 30 | | | | | | | | | | 31 Sundries unknown | | | | | | | | | | 32 | | | | | | | | | | 33 | | | | | | | | | | 34 Total flying weight | | |11,775| 26 | | | | | | 35 | | | | | | | | | | 36 | | | | | | | | | | 37 | | | | | | | | | | 38 Total area of support (not | | | | | including tail) sq. ft. | |68 | | | | | | | | 39 Total area of support in feet, | | | | | divided by total flying weight in lbs. | | 2.6 | | | | | | | | 40 Total area of horizontal tail sq. | | | | | ft. | | | | | | | | | | 41 Total area of rudder (vertical) | | | | | sq. ft. | | 6 | | | | | | | | 42 Horse-power at brake. Horse-power | | | | | by formula* .72 | | 7 | | | | | | | | 43 Minimum pressure during 40 secs. | | | | | lift, 150 lbs. | | | | | | | | | | 44 Lift at pendulum (during 40 secs. | | | | | absolute) 5772 | | | | | | | | | | 45 Lift at pendulum (during 40 secs. | | | | | in terms of wt.) 49% | | | | | | | | | | 46 Minimum pressure with which wheels | | | | | turn, 10 lbs. | | | | | | | | | | 47 Position of center of pressure of | | | | | wings† F. W., 1575; R. W., 1383.5 | | | | | | | | | | 48 Time of getting up full steam, 1 | | | | | minute | | | | | | | | | | 49 | | | | | | | | | | 50 Curvature of wings, 1/11 | | | | | | | | | | 51 Root angle of wings, 9° | | | | | | | | | | 52 Tip angle of wings, 9° | | | | | | | | | | 53 Position of wings, Front rib on F. | | | | | W., 1607; R. W., 1415.5 | | | | | | | | | | 54 How guyed | | | | | | | | | | 55 | | | | | | | | | | 56 | | | | | | | | | | 57 | | | | | | | | | | 58 Position of tail | | | | | | | | | | 59 Angle of tail | | | | | | | | | | 60 Co-efficient elasticity of tail | | | | | | | | | | 61 Position of rudder, center, | | | | | 1288.3; rear end, 1229.8 | | | | | | | | | | 62 Line of thrust, 2500 | | | | | | | | | | 63 Line of thrust, 1500 which is 9 | | | | | cm. below the center of midrod | | | | | | | | | | 64 Center of gravity_1 of whole, 1497 | | | | | | | | | | 65 Center of gravity_2 2501, i. e., 1 | | | | | cm. above line of thrust | | | | | | | | | | 66 Center of pressure_1 of whole | | | | | estimate, 1498 | | | | | | | | | | 67 Center of pressure_2, 2536 | | | | | | | | | | 68 | | | | | | | | | | 69 | | | | | | | | | | 70 | | | | | | | | | | 71 | | | | | | | | | | 72 | | | | | ---------------------------------------+----+-----+------+------+

Parts. Remarks.

1 Front end of bowsprit, 1686.3.

2 Front end of midrod, 1611.6.

5 Front edge of F. W., 1607.

8 C. of P. on F. W., 1575.

11 Back edge of F. W., 1527.

14 Back edge of cross frame, 1509.

17 Line through center of propellers, 1500.

21 C. of G., 1497.

24 Front edge of R. W., 1415.5.

27 C. of P. on R. W., 1383.5.

30 End of mid-rod, 1360.5.

33 Front end of rudder, 1343.8.

36 Back edge of R. W., 1335.5.

39 Center of rudder, 1288.3.

41 Back end of rudder, 1229.8.

* H. P. = (Rev.×diam.×pitch ratio×thrust)/33000

† This is calculated on the assumption that the center of pressure on each wing or on pair of wings at a motion of 2000 feet per minute is in ordinary curved wings 2-5 the way from front to rear, that for wings of usual size the rear wings have 2-3 of the efficiency per surface of the front ones and that the tail proper bears no part of the weight; but if rear wing is smaller or larger this efficiency is smaller or larger per unit of surface.

[p298]

DATA SHEET No. 2.

Weight of Aerodrome No. 6. Certified to by R. L. Reed, November 27 and 28, 1896.

-------------------------------------------+-----------+-------------+ Parts. | Sizes. | Weight. | -------------------------------------------+-----+-----+------+------+ |‹m.› |‹ft.›|‹gr.› |‹lbs.›| 1 Frame, including everything of metal, | | | | | permanent and undetachable, such as bed-| | | | | plate, cross-rods for the support of | | | | | propellers, bearing points for clutch, | | | | | etc. | | | 1178| | 2 Engine, gears, shafts, etc. | | | 1043| | | | | | | 3 Pump, pump shaft | | | 190| | 4 Hull covering | | | 345| | 5 Gasoline tanks, valves | | | 306| | 6 Smokestack, 302; burner, 172 | | | 474| | 7 Float | | | 275| | 8 Reel | | | 77| | 9 Wing clamps, 238; drop piece for rudder, | | | 278| | 40 | | | | | 10 Other things | | | 156| | 11 Boiler, frames, mica cover | | | 694| | 12 Separator, steam gauge, pipe to engines | | | 535| | 13 Exhaust pipe | | | 82| | 14 | | | | | 15 | | | | | 16 | | | | | 17 Wings (without clamp), wet | | | 2154| | 18 Tail (without clamp) | | | | | 19 Rudder | | | 375| | 20 Guy sticks, each 53 | | | 106| | 21 Propellers | | | 644| | 22 Extra length of midrod | | | 398| | 23 Wood bowsprit | | | 135| | 24 Counter | | | 75| | 25 | | | | | 26 | | | | | 27 Fuel (at starting flight) | | | 250| | 28 Water (at starting flight) | | | 2350| | 29 | | | | | 30 | | | | | 31 Sundries unknown | | | | | 32 | | | | | 33 | | | | | 34 Total flying weight | | |12,120| | 35 | | | | | 36 | | | | | 37 | | | | 38 Total area of support (not including | | 54| | | tail) sq. ft. | | | | | 39 Total area of support in feet, divided | | | | | by total flying weight in lbs. | | 2 | | | 40 Total area of horizontal tail sq. ft.| .6 | | | | 41 Total area of rudder (vertical) sq. ft.| .6 | | | | 42 Horse-power at brake Horse-power by | | | | | formula* | | | | | 43 Minimum steam pressure during 40 secs. | | | | 130| lift | | | | | 44 Lift at pendulum (during one minute | | | | 7,211| absolute) | | | | | 45 Lift at pendulum (during one minute in | | | | | terms of wt.) | | | | | 46 Minimum pressure with which wheels turn | | | | 10 | 47 Position of center of pressure of wings†| | | | | 48 Time of getting up full steam, 75 secs. | | | | | 49 Angle of midrod with horizon, 2° 17′ | | | | | 50 Curvature of wings, 1 in 18, 1/4 from | | | | | front | | | | | 51 Root angle of wings, 10° 30′ | | | | | 52 Tip angle of wings, 10° 30′ | | | | | 53 Position of wings | | | | | 54 How guyed | | | | | 55 | | | | | 56 | | | | | 57 | | | | | 58 Position of tail | | | | | 59 Angle of tail | | | | | 60 Co-efficient elasticity of tail | | | | | 61 Position of rudder | | | | | 62 | | | | | 63 Line of thrust 1500 | | | | | 64 Center of gravity_1 of whole, 1483.8 | | | | | 65 Center of gravity_2, 2482‡ | | | | | 66 Center of pressure_1 of whole | | | | | estimate, 1487 | | | | | 67 Center of pressure_2, 2520 | | | | | 68 | | | | | 69 | | | | | 70 | | | | | 71 | | | | | 72 | | | | | -------------------------------------------+-----+-----+------+------+

Parts. Remarks.

1 Front end of bowsprit, 1797.

2 Center of float in first trial, Nov.

6 Front end of midrod, 1613.7. 9 Front edge of F. W., 1595.7.

12 Center of float in flight, Nov. 28, 1896, 1575.8.

16 C. of P. on F. W., 1563.7.

19 Back edge of F. W., 1515.7.

22 Line through center

of propellers, 1500.

26 C. of G., 1484.4 (old C. of G., 1486.3).

29 Front edge of R. W., 1406.

32 C. of P. on R. W., 1374.

35 End of midrod, 1351.3

38 Front end of rudder, 1334.5.

41 Back edge of R. W., 1326.

43 Center of rudder, 1279.

46 Back end of rudder, 1220.5.

49 Reed wings, 80 cm.×185 cm. in rectangle.

53 Weight in shop, 1982 g.

56 On day of flight they weighed 2154 g. because they were damp.

60 Area 54 sq. ft.

63 Spread of wings, 359 cms. or 11′ 9-3/8″.

67 Weight of aerodrome in flight, 12,120 grs.

* H. P. = (Rev.×diam.×pitch ratio×thrust)/33000

† This is calculated on the assumption that the center of pressure on each wing or on pair of wings at a motion of 2000 feet per minute is in ordinary curved wings 2-5 the way from front to rear, that for wings of usual size the rear wings have 2-3 of the efficiency per surface of the front ones and that the tail proper bears no part of the weight; but if rear wing is smaller or larger this efficiency is smaller or larger per unit of surface.

‡ This is undoubtedly incorrect, as if it were true, the C. G. would be just at the center of the separator, and this would be impossible. Mr. Reed states that the C. G. was 2 cm. below the side frame, and if this is correct, we would have C. G. = 2486.

[p299]

DATA SHEET No. 3.

Weight of Aerodrome No. 6, Flat Wings and Pénaud Rudder. Certified to by Chas. M. Manly, June 7, 1899.

---------------------------------------+----------+-------------+ Parts. | Sizes. | Weight. | ---------------------------------------+----+-----+------+------+ |‹m.›|‹ft.›|‹gr.› |‹lbs.›| 1 Frame, including everything of | | | | | metal, permanent and undetachable, | | | | | such as bed-plate, cross-rods for the | | | | | support of propellers, bearing points | | | | | for clutch, etc. | | | 2867| | | | | | | 2 Engine, gears, shafts, etc. | | | | | | | | | | 3 Pump, 123; pump shaft, 49 | | | 172| | | | | | | 4 Hull covering, including apron and | | | | | piece behind separator | | | 274| | | | | | | 5 Gasoline and air tanks, 167, 114; | | | | | air valve, 16 | | | 297| | | | | | | 6 Smokestack, 319; counter, 95; | | | | | burner, 165 | | | 679| | | | | | | 7 Float, 275; pipe from pump to | | | | | boiler, 40 | | | 315| | | | | | | 8 Reel, with fork and float | | | 128| | | | | | | 9 Wing clamps, 188; guy-post clamps, | | | 212| | 24 | | | | | | | | | | 10 Boiler, 764; steam gauge and | | | | | connections, 79 | | | 843| | | | | | | 11 Front lower bearing post, 75; | | | | | clutch post, 58; rear bearing points, | | | 288| | 155 | | | | | | | | | | 12 Separator and pipes leading to | | | | | engines and pump | | | 502| | | | | | | 13 Drop piece for rudder, 57; | | | 75| | guy-post for rudder, 18 | | | | | | | | | | 14 | | | | | | | | | | 15 | | | | | | | | | | 16 | | | | | | | | | | 17 Wings (without clamp) | | | 2077| | | | | | | 18 Superposed wings, 3448 | | | | | | | | | | 19 Rudder | | | 323| | | | | | | 20 Guy sticks, each 53 | | | 106| | | | | | | 21 Propellers | | | 620| | | | | | | 22 Extra length of midrod | | | 377| | | | | | | 23 Wood bowsprit | | | 128| | | | | | | 24 Canvas keel, 36; rudder, 76 | | | 112| | | | | | | 25 | | | | | | | | | | 26 | | | | | | | | | | 27 Fuel (at starting flight) | | | 175| | | | | | | 28 Water (at starting flight) | | | 1525| | | | | | | 29 | | | | | | | | | | 30 | | | | | | | | | | 31 Sundries unknown | | | | | | | | | | 32 | | | | | | | | | | 33 | | | | | | | | | | 34 Total flying weight | | |11,995| 26.44| | | | | | 35 | | | | | | | | | | 36 | | | | | | | | | | 37 | | | | | | | | | | 38 Total area of support (not | | | | | including tail) sq. ft. | |54 | | | | | | | | 39 Total area of support in feet, | | | | | divided by total flying weight in lbs. | | 2.04| | | | | | | | 40 Total area of horizontal tail sq. | | | | | ft. | | 9.5 | | | | | | | | 41 Total area of rudder (vertical) | | | | | sq. ft. | | 7.75| | | | | | | | 42 Horse-power at brake Horse-power | | | | | by formula* | | | | | | | | | | 43 | | | | | | | | | | 44 Lift at pendulum (during one | | | | | minute absolute) | | | | | | | | | | 45 Lift at pendulum (during one | | | | | minute in terms of wt.) | | | | | | | | | | 46 Minimum pressure with which wheels | | | | | turn | | | | | | | | | | 47 Position of center of pressure of | | | | | wings† 40% from front | | | | | | | | | | 48 | | | | | | | | | | 49 | | | | | | | | | | 50 Curvature of wings, 1 in 18 | | | | | | | | | | 51 Root angle of wings, 10° | | | | | | | | | | 52 Tip angle of wings, 10° | | | | | | | | | | 53 Position of wings--front edge of | | | | | front wing, 1595.7; of rear wing, | | | | | 1406.5 | | | | | | | | | | 54 How guyed--with wires from wing to | | | | | wing on top and to guy-post on bottom | | | | | | | | | | 55 | | | | | | | | | | 56 | | | | | | | | | | 57 | | | | | | | | | | 58 Position of center of rudder, | | | | | 1279.5 | | | | | | | | | | 59 Angle of tail, 10° | | | | | | | | | | 60 Co-efficient elasticity of tail | | | | | | | | | | 61 Position of rudder | | | | | | | | | | 62 | | | | | | | | | | 63 Line of thrust, 1500 | | | | | | | | | | 64 Center of gravity_1 of whole, | | | | | 1484.4 | | | | | | | | | | 65 Center of gravity_2 | | | | | | | | | | 66 Center of pressure_1 of whole | | | | | estimate | | | | | | | | | | 67 Center of pressure_2 | | | | | | | | | | 68 | | | | | | | | | | 69 | | | | | | | | | | 70 | | | | | | | | | | 71 | | | | | | | | | | 72 | | | | |

Parts. Remarks.

1 Front edge of bowsprit, 1702.7. Weight 2867 gm. for part 1 includes also part 2.

2 Center of float with small wind vane rudder, 1628.9.

6 Front edge of midrod, 1613.7.

9 Center of float with small rudder off, 1609.2.

12 Front edge of F. W., 1595.7.

15 C. of P. on F. W., 1563.7.

18 Back edge of F. W., 1515.7.

21 Line through center of propellers, 1500.

25 C. of G., 1484.4.

28 Front edge of R. W., 1406.5.

31 C. of P. on R. W., 1374.5.

34 End of midrod, 1351.8.

37 Front end of rudder, 1335.

39 Back edge of R. W., 1326.5.

42 Center of rudder, 1279.5.

45 Back end of rudder, 1221.

* H. P. = (Rev.×diam.×pitch ratio×thrust)/33000

† This is calculated on the assumption that the center of pressure on each wing or on pair of wings at a motion of 2000 feet per minute is in ordinary curved wings 2-5 the way from front to rear, that for wings of usual size the rear wings have 2-3 of the efficiency per surface of the front ones and that the tail proper bears no part of the weight; but if rear wing is smaller or larger this efficiency is smaller or larger per unit of surface.

[p300]

DATA SHEET No. 4.

Weight of Aerodrome No. 6, Superposed Wings and Pénaud Rudder. Certified to by Chas. M. Manly, June 13, 1899.

---------------------------------------+----------+-------------+ Parts. | Sizes. | Weight. | ---------------------------------------+----+-----+------+------+ |‹m.›|‹ft.›|‹gr.› |‹lbs.›| 1 Frame, including everything of | | | | | metal, permanent and undetachable, | | | | | such as bed-plate, cross-rods for the | | | | | support of propellers, bearing points | | | | | for clutch, etc. | | | 2867| | | | | | | 2 Engine, gears, shafts, etc. | | | | | | | | | | 3 Pump, 123; pump shaft, 49 | | | 172| | | | | | | 4 Hull covering, including apron and | | | | | piece behind separator | | | 274| | | | | | | 5 Gasoline and air tanks, 167, 114; | | | | | air valve, 16 | | | 297| | | | | | | 6 Smokestack, 319; counter, 95; | | | | | burner, 170 | | | 584| | | | | | | 7 Float | | | 315| | | | | | | 8 Reel, with fork and float | | | 128| | | | | | | 9 Wing clamps, 188; guy-post clamps, | | | | | 24 | | | 212| | | | | | | 10 Boiler, 764; steam gauge and | | | | | connections, 79 | | | 843| | | | | | | 11 Front bearing point, 75; clutch | | | | | post, 58; rear bearing points, 155 | | | 288| | | | | | | 12 Separator and pipes to engines and | | | | | pump | | | 502| | | | | | | 13 Drop piece and guy-post for rudder | | | 75| | | | | | | 14 | | | | | | | | | | 15 | | | | | | | | | | 16 | | | | | | | | | | 17 Wings (without clamp), 2077; | | | | | superposed wings | | | 3448| | | | | | | 18 Tail (without clamp) | | | | | | | | | | 19 Rudder | | | 323| | | | | | | 20 Guy sticks | | | 106| | | | | | | 21 Propellers | | | 620| | | | | | | 22 Extra length of midrod | | | 377| | | | | | | 23 Wood bowsprit | | | 128| | | | | | | 24 Canvas keel, 36 | | | 36| | | | | | | 25 | | | | | | | | | | 26 | | | | | | | | | | 27 Fuel (at starting flight) | | | 175| | | | | | | 28 Water (at starting flight) | | | 1525| | | | | | | 29 | | | | | | | | | | 30 | | | | | | | | | | 31 Sundries unknown | | | | | | | | | | 32 | | | | | | | | | | 33 | | | | | | | | | | 34 Total flying weight | | |13,275| | | | | | | 35 | | | | | | | | | | 36 | | | | | | | | | | 37 | | | | | | | | | | 38 Total area of support (not | | | | | including tail) sq. ft. | |87.4 | | | | | | | | 39 Total area of support in feet, | | | | | divided by total flying weight in lbs | | | | | | | | | | 40 Total area of horizontal tail sq. | | 9.5 | | | ft. | | | | | | | | | | 41 Total area of rudder (vertical) | | 7.75| | | sq. ft. | | | | | | | | | | 42 Horse-power at brake Horse-power | | | | | by formula* | | | | | | | | | | 43 | | | | | | | | | | 44 Lift at pendulum (during one | | | | | minute absolute) | | | | | | | | | | 45 Lift at pendulum (during one | | | | | minute in terms of wt.) | | | | | | | | | | 46 Minimum pressure with which wheels | | | | | turn | | | | | | | | | | 47 Position of center of pressure of | | | | | wings†, 40% from front | | | | | | | | | | 48 | | | | | | | | | | 49 | | | | | | | | | | 50 Curvature of wings, 1 in 18 | | | | | | | | | | 51 Root angle of wings, 10° | | | | | | | | | | 52 Tip angle of wings, 10° | | | | | | | | | | 53 Position of wings--front edge of | | | | | front wing, 159 | | | | | | | | | | 54 How guyed | | | | | | | | | | 55 | | | | | | | | | | 56 | | | | | | | | | | 57 | | | | | | | | | | 58 Position of tail | | | | | | | | | | 59 Angle of tail, 7-1/2° | | | | | | | | | | 60 Co-efficient elasticity of tail, | | | | | 1240 grammes at center to deflect to | | | | | the horizontal | | | | | | | | | | 61 Position of rudder | | | | | | | | | | 62 | | | | | | | | | | 63 Line of thrust, 1500 | | | | | | | | | | 64 Center of gravity_1 of whole, | | | | | 1484.4 | | | | | | | | | | 65 Center of gravity_2 | | | | | | | | | | 66 Center of pressure_1 of whole | | | | | estimate | | | | | | | | | | 67 Center of pressure_2 | | | | | | | | | | 68 | | | | | | | | | | 69 | | | | | | | | | | 70 | | | | | | | | | | 71 | | | | | | | | | | 72 | | | | | ---------------------------------------+----+-----+------+------+

Parts. Remarks.

1 Front edge of bowsprit, 1702.7. Weight 2867 gm. includes parts 2.

2 Center of float without small wind vane rudder, 1666.1. (Center of float with wind vane rudder on, 1627.)

8 Front edge of midrod, 1613.7.

11 Front edge of F. W., 1585.

13 C. of P. on F. W., 1563.7.

16 Rear edge of F. W., 1531.7.

19 Line through center of propellers, 1500.

23 C. of G., 1484.4.

26 Front edge of R. W., 1395.8.

29 C. of P. on R. W., 1374.5.

32 End of midrod, 1351.8.

35 Front end of rudder, 1335.

38 Back edge of R. W., 1342.5.

40 Center of rudder, 1279.5.

43 Back end of rudder, 1221.

* H. P. = (Rev.×diam.×pitch ratio×thrust)/33000

† This is calculated on the assumption that the center of pressure on each wing or on pair of wings at a motion of 2000 feet per minute is in ordinary curved wings 2-5 the way from front to rear, that for wings of usual size the rear wings have 2-3 of the efficiency per surface of the front ones and that the tail proper bears no part of the weight; but if rear wing is smaller or larger this efficiency is smaller or larger per unit of surface.

[p301]

DATA SHEET No. 5.

Weight of Aerodrome No. 6, Flat Wings and Pénaud Rudder. Certified to by Chas. M. Manly, June 22, 1899.

---------------------------------------+----------+-------------+ Parts. | Sizes. | Weight. | ---------------------------------------+----+-----+------+------+ |‹m.›|‹ft.›|‹gr.› |‹lbs.›| 1 Frame, including everything of | | | | | metal, permanent and undetachable, | | | | | such as bed-plate, cross-rods for the | | | | | support of propellers, bearing points | | | | | for clutch, etc. (bowsprit, 78g) | | | 2867| | | | | | | 2 Engine, gears, shafts, etc. | | | | | | | | | | 3 Pump, 123; pump shaft, 49 | | | 172| | | | | | | 4 Hull covering, including apron and | | | | | piece behind separator | | | 274| | | | | | | 5 Gasoline and air tanks, 167, 174; | | | | | air valve, 16 | | | 357| | | | | | | 6 Smokestack, 319; counter, 95; | | | | | burner, 170 | | | 584| | | | | | | 7 Float | | | 315| | | | | | | 8 Reel, with fork and float | | | 128| | | | | | | 9 Wing clamps, 188; guy-post clamps, | | | | | 24 | | | 212| | | | | | | 10 Boiler, 764; steam gauge and | | | | | connections, 79 | | | 843| | | | | | | 11 Front bearing post, 75; | | | | | clutch-post, 58 | | | 133| | | | | | | 12 Rear bearing points | | | 155| | | | | | | 13 Separator and pipes to engines and | | | | | pump | | | 502| | | | | | | 14 Drop piece and guy-posts, 18; for | | | | | rudder, 57 | | | 75| | | | | | | 15 | | | | | | | | | | 16 | | | | | | | | | | 17 Wings (without clamp) | | | 2077| | | | | | | 18 Tail (without clamp) | | | | | | | | | | 19 Rudder | | | 323| | | | | | | 20 Guy sticks | | | 106| | | | | | | 21 Propellers | | | 620| | | | | | | 22 Extra length of midrod | | | 377| | | | | | | 23 Wood bowsprit | | | 128| | | | | | | 24 Other things | | | | | | | | | | 25 | | | | | | | | | | 26 | | | | | | | | | | 27 Fuel (at starting flight) | | | 175| | | | | | | 28 Water (at starting flight) | | | 1525| | | | | | | 29 | | | | | | | | | | 30 | | | | | | | | | | 31 Sundries unknown | | | | | | | | | | 32 | | | | | | | | | | 33 | | | | | | | | | | 34 Total flying weight | | |11,948| 26.3 | | | | | | 35 | | | | | | | | | | 36 | | | | | | | | | | 37 | | | | | | | | | | 38 Total area of support (not | | | | | including tail) sq. ft. | |54 | | | | | | | | 39 Total area of support in feet, | | | | | divided by total flying weight in lbs. | | | | | | | | | | 40 Total area of horizontal tail sq. | | | | | ft. | | 9.5 | | | | | | | | 41 Total area of rudder (vertical) | | | | | sq. ft. | | 7.75| | | | | | | | 42 Horse-power at brake Horse-power | | | | | by formula* | | | | | | | | | | 43 | | | | | | | | | | 44 Lift at pendulum (during one | | | | | minute absolute) | | | | | | | | | | 45 Lift at pendulum (during one | | | | | minute in terms of wt.) | | | | | | | | | | 46 Minimum pressure with which wheels | | | | | turn | | | | | | | | | | 47 Position of center of pressure of | | | | | wings† 40% from front | | | | | | | | | | 48 | | | | | | | | | | 49 | | | | | | | | | | 50 Curvature of wings, 1 in 18 | | | | | | | | | | 51 Root angle of wings, 10° | | | | | | | | | | 52 Tip angle of wings, 10° | | | | | | | | | | 53 Position of wings | | | | | | | | | | 54 How guyed | | | | | | | | | | 55 | | | | | | | | | | 56 | | | | | | | | | | 57 | | | | | | | | | | 58 Position of tail | | | | | | | | | | 59 Angle of tail, 7° 30′ | | | | | | | | | | 60 Co-efficient elasticity of tail, | | | | | 1240 grammes at center to deflect to | | | | | the horizontal | | | | | | | | | | 61 Position of rudder | | | | | | | | | | 62 | | | | | | | | | | 63 Line of thrust, 1500 | | | | | | | | | | 64 Center of gravity_1 of whole | | | | | | | | | | 65 Center of gravity_2 | | | | | | | | | | 66 Center of pressure_1 of whole | | | | | estimate | | | | | | | | | | 67 Center of pressure_2 | | | | | | | | | | 68 | | | | | | | | | | 69 | | | | | | | | | | 70 | | | | | | | | | | 71 | | | | | | | | | | 72 | | | | | ---------------------------------------+----+-----+------+------+

Parts. Remarks.

1 Front edge of bowsprit, 1685.7. Weight 2867 gm. includes Parts 2.

2 Back edge of cylindrical part of float, 1606.5

5 Front edge of midrod, 1613.7.

8 Front edge of F. W., 1595.7.

11 C. of P. on F. W., 1563.7.

14 Back edge of F. W., 1515.7.

17 Line through center of propellers, 1500.

21 C. of G., 1484.4.

24 Front edge R. W., 1406.5.

27 C. of P. on R. W., 1374.5.

30 End of midrod, 1351.8.

33 Front end of rudder, 1335.

36 Back edge R. W., 1326.5.

38 Center of rudder, 1279.5.

41 Back end of rudder, 1221.

* H. P. = (Rev.×diam.×pitch ratio×thrust)/33000

† This is calculated on the assumption that the center of pressure on each wing or on pair of wings at a motion of 2000 feet per minute is in ordinary curved wings 2-5 the way from front to rear, that for wings of usual size the rear wings have 2-3 of the efficiency per surface of the front ones and that the tail proper bears no part of the weight; but if rear wing is smaller or larger this efficiency is smaller or larger per unit of surface.

[p302]

DATA SHEET No. 6.

Weight of Aerodrome No. 5, Flat Wings and Pénaud Rudder. Certified to by Chas. M. Manly, June 23, 1899.

---------------------------------------+----------+-------------+ Parts. | Sizes. | Weight. | ---------------------------------------+----+-----+------+------+ |‹m.›|‹ft.›|‹gr.› |‹lbs.›| 1 Frame, including everything of | | | | | metal, permanent and undetachable, | | | | | such as bed-plate, cross-rods for the | | | | | support of propellers, bearing points | | | | | for clutch, etc. | | | 3050| | | | | | | 2 Engine | | | 464| | | | | | | 3 Pump, 334; pump shaft, 55 | | | 389| | | | | | | 4 Hull covering | | | 398| | | | | | | 5 Gasoline tanks, air tanks, valves, | | | | | etc. | | | 348| | | | | | | 6 Smokestack | | | 373| | | | | | | 7 Float, 275; drop piece for rudder, | | | | | 57; guy-post, 18 | | | 350| | | | | | | 8 Reel, 128; steam gauge, 81 | | | 209| | | | | | | 9 Wing clamps, 200; guy-post clamps, | | | | | 32 | | | 232| | | | | | | 10 Boiler, 764; burner, 170; counter, | | | | | 95 | | | 1029| | | | | | | 11 Rear extension to midrod | | | 174| | | | | | | 12 Separator and pipes to engine and | | | | | pump | | | 502| | | | | | | 13 Exhaust pipe | | | 84| | | | | | | 14 Front lower bearing point, 84; | | | | | clutch post, 41 | | | 125| | | | | | | 15 Rear bearing points, 146; extra | | | | | strengtheners, 32 | | | 178| | | | | | | 16 | | | | | | | | | | 17 Wings (without clamp) | | | 2342| | | | | | | 18 Tail (without clamp) | | | | | | | | | | 19 Rudder | | | 322| | | | | | | 20 Guy sticks, each 56 | | | 112| | | | | | | 21 Propellers | | | 837| | | | | | | 22 Extra length of midrod at front | | | 129| | | | | | | 23 Wood bowsprit | | | 132| | | | | | | 24 Other things | | | | | | | | | | 25 | | | | | | | | | | 26 | | | | | | | | | | 27 Fuel (375 at starting flight) | | | 200| | | | | | | 28 Water (2100 at starting flight) + | | | | | 616 in boiler | | | 1400| | | | | | | 29 | | | | | | | | | | 30 | | | | | | | | | | 31 Sundries unknown | | | | | | | | | | 32 | | | | | | | | | | 33 | | | | | | | | | | 34 Total flying weight | | |13,370| | | | | | | 35 | | | | | | | | | | 36 | | | | | | | | | | 37 | | | | | | | | | | 38 Total area of support (not | | | | | including tail) sq. ft. | |68 | | | | | | | | 39 Total area of support in feet, | | | | | divided by total flying weight in lbs | | | | | | | | | | 40 Total area of horizontal tail sq. | | | | | ft. | | 6.94| | | | | | | | 41 Total area of rudder (vertical) | | | | | sq. ft. | | 7.64| | | | | | | | 42 Horse-power at brake Horse-power | | | | | by formula* | | | | | | | | | | 43 | | | | | | | | | | 44 Lift at pendulum (during one | | | | | minute absolute) | | | | | | | | | | 45 Lift at pendulum (during one | | | | | minute in terms of wt.) | | | | | | | | | | 46 Minimum pressure with which wheels | | | | | turn | | | | | | | | | | 47 Position of center of pressure of | | | | | wings† | | | | | | | | | | 48 | | | | | | | | | | 49 | | | | | | | | | | 50 Curvature of wings | | | | | | | | | | 51 Root angle of wings, 10° | | | | | | | | | | 52 Tip angle of wings, 10° | | | | | | | | | | 53 Position of wings | | | | | | | | | | 54 How guyed | | | | | | | | | | 55 | | | | | | | | | | 56 | | | | | | | | | | 57 | | | | | | | | | | 58 Position of tail | | | | | | | | | | 59 Angle of tail, 7° 30′ | | | | | | | | | | 60 Co-efficient elasticity of tail | | | | | | | | | | 61 Position of rudder | | | | | | | | | | 62 | | | | | | | | | | 63 Line of thrust, 1500 | | | | | | | | | | 64 Center of gravity_1 of whole | | | | | | | | | | 65 Center of gravity_2 | | | | | | | | | | 66 Center of pressure_1 of whole | | | | | estimate | | | | | | | | | | 67 Center of pressure_2 | | | | | | | | | | 68 | | | | | | | | | | 69 | | | | | | | | | | 70 | | | | | | | | | | 71 | | | | | | | | | | 72 | | | | | ---------------------------------------+----+-----+------+------+

Parts. Remarks.

1 Front end of midrod, 1611.5.

2 Front edge of F. W., 1609.7.

5 C. of P. on F. W., 1577.7.

8 Back edge of F. W., 1529.7.

11 Line through center of propellers, 1500.

15 C. of G., 1494.6.

18 Front edge of R. W., 1411.7.

21 C. of P. on R. W., 1379.7.

24 Rear end of midrod, 1360.3.

27 Rear end of R. W., 1331.7.

* H.P = (Rev.×diam.×pitch ratio×thrust)/33000

† This is calculated on the assumption that the center of pressure on each wing or on pair of wings at a motion of 2000 feet per minute is in ordinary curved wings 2-5 the way from front to rear, that for wings of usual size the rear wings have 2-3 of the efficiency per surface of the front ones and that the tail proper bears no part of the weight; but if rear wing is smaller or larger this efficiency is smaller or larger per unit of surface.

[p303]

DATA SHEET No. 7.

Weight of Aerodrome No. 5, Flat Wings and Pénaud Rudder. Certified to by Chas. M. Manly, July 12, 1899.

---------------------------------------+----------+-------------+ Parts. | Sizes. | Weight. | ---------------------------------------+----+-----+------+------+ |‹m.›|‹ft.›|‹gr.› |‹lbs.›| 1 Frame, including everything of | | | | | metal, permanent and undetachable, | | | | | such as bed-plate, cross-rods for the | | | | | support of propellers, bearing points | | | | | for gears, clutch, shafts, etc. | | | 3050| | | | | | | 2 Engine | | | 464| | | | | | | 3 Pump, 334; pump shaft, with gear | | | | | and eccentric and end rod, 55 | | | 389| | | | | | | 4 Hull Covering, 264; apron 115; | | | | | piece behind separator, 19 | | | 398| | | | | | | 5 Gasoline and air tanks, 167, 165; | | | | | air valve, 16 | | | 348| | | | | | | 6 Smokestack, 310; piece to protect | | | | | midrod, 63 | | | 373| | | | | | | 7 Float, 275; drop piece for rudder, | | | | | 57; guy-post, 18 | | | 350| | | | | | | 8 Reel, fork and float, 128; steam | | | | | gauge with pipe, 81 | | | 209| | | | | | | 9 Wing clamps, 200; guy-post clamps, | | | | | 32 | | | 232| | | | | | | 10 Boiler, 764; burner, 170; counter, | | | | | 95 | | | 1029| | | | | | | 11 Rear extension to midrod | | | 174| | | | | | | 12 Separator and pipes to engine and | | | | | pump | | | 502| | | | | | | 13 Exhaust pipe, 84 | | | 84| | | | | | | 14 Front lower bearing point, 84; | | | | | clutch post, 41 | | | 125| | | | | | | 15 Rear bearing points, 146; extra | | | | | strengtheners, 32 | | | 178| | | | | | | 16 | | | | | | | | | | 17 Wings (without clamp) (2180 in | | | | | 1896) | | | 2342| | | | | | | 18 Tail (without clamp); part of | | | | | rudder | | | | | | | | | | 19 Rudder reduced (No. 2 or new one, | | | | | 299) | | | 322| | | | | | | 20 Guy sticks, each 56 | | | 112| | | | | | | 21 Propellers (95 cms.; wood, 837; 95 | | | | | cms. canvas, 548) | | | 837| | | | | | | 22 Extra length of midrod (front), 129 | | | 129| | | | | | | 23 Wood bowsprit (complete), 132 | | | 132| | | | | | | 24 Other things | | | | | | | | | | 25 | | | | | | | | | | 26 | | | | | | | | | | 27 Fuel (375 at starting flight) | | | 200| | | | | | | 28 Water (2100 at starting flight) + | | | | | 616 in boiler | | | 1400| | | | | | | 29 | | | | | | | | | | 30 | | | | | | | | | | 31 Sundries unknown | | | | | | | | | | 32 | | | | | | | | | | 33 | | | | | | | | | | 34 Total flying weight | | |13,379| | | | | | | 35 | | | | | | | | | | 36 | | | | | | | | | | 37 | | | | | | | | | | 38 Total area of support (not | | | | | including tail) sq. ft. | |68 | | | | | | | | 39 Total area of support in feet, | | | | | divided by total flying weight in lbs. | | | | | | | | | | 40 Total area of horizontal tail sq. | | 6.94| | | ft. | | | | | | | | | | 41 Total area of rudder (vertical) | | | | | sq. ft. | | 7.64| | | | | | | | 42 Horse-power at brake Horse-power | | | | | by formula* | | | | | | | | | | 43 | | | | | | | | | | 44 Lift at pendulum (during one | | | | | minute absolute) | | | | | | | | | | 45 Lift at pendulum (during one | | | | | minute in terms of wt.) | | | | | | | | | | 46 Minimum pressure with which wheels | | | | | turn | | | | | | | | | | 47 Position of center of pressure of | | | | | wings† | | | | | | | | | | 48 | | | | | | | | | | 49 | | | | | | | | | | 50 Curvature of wings, 1 in 12 | | | | | | | | | | 51 Root angle of wings, 10° | | | | | | | | | | 52 Tip angle of wings, 10° | | | | | | | | | | 53 Position of wings | | | | | | | | | | 54 How guyed | | | | | | | | | | 55 | | | | | | | | | | 56 | | | | | | | | | | 57 | | | | | | | | | | 58 Position of tail | | | | | | | | | | 59 Angle of tail, 7° 30′ | | | | | | | | | | 60 Co-efficient elasticity of tail, | | | | | 1240 grammes at center of rudder to | | | | | bring it to a horizontal; 490 grammes | | | | | at point same distance from front | | | | | end of rudder as length of rudder of | | | | | 1896, to bring to horizontal | | | | | | | | | | 61 Position of rudder | | | | | | | | | | 62 | | | | | | | | | | 63 Line of thrust, 1500 | | | | | | | | | | 64 Center of gravity_1 of whole | | | | | | | | | | 65 Center of gravity_2 | | | | | | | | | | 66 Center of pressure_1 of whole | | | | | estimate | | | | | | | | | | 67 Center of pressure_2 | | | | | | | | | | 68 | | | | | | | | | | 69 | | | | | | | | | | 70 | | | | | | | | | | 71 | | | | | | | | | | 72 | | | | | ---------------------------------------+----+-----+------+------+

Parts. Remarks.

1 Front end of bowsprit, 1700.5. Front end of midrod 1611.5.

3 Front edge of F. W., 1609.7.

6 C. of P. on F. W., 1577.7.

9 Rear edge of F. W., 1529.7.

12 Line through center of propellers 1500.

16 Front edge of R. W., 1411.7.

19 C. of P. on R. W., 1379.7.

22 End of midrod, 1360.3.

25 Front end of rudder, 1343.5.

28 Back edge of R. W., 1331.7.

31 Center of rudder, 1288.

34 Back end of rudder, 1229.5.

* H.P. = (Rev.×diam.×pitch ratio×thrust) / 33000

† This is calculated on the assumption that the center of pressure on each wing or on a pair of wings at a motion of 2000 feet per minute is in ordinary curved wings 2-5 the way from the front to the rear, that for wings of usual size the rear wing have 2-3 of the efficiency per surface of the front ones and that the tail proper bears no part of the weight; but if rear wing is smaller or larger this efficiency is smaller or larger per unit of surface.

[p304]

DATA SHEET No. 8.

Weight of Aerodrome No. 5, Flat Wings and Pénaud Rudder. Certified to by Chas. M. Manly, July 19, 1899.

---------------------------------------+----------+-------------+ Parts. | Sizes. | Weight. | ---------------------------------------+----+-----+------+------+ |‹m.›|‹ft.›|‹gr.› |‹lbs.›| 1 Frame, including everything of | | | | | metal, permanent and undetachable, | | | | | such as bed-plate, cross-rods for the | | | | | support of propellers, bearing points | | | | | for clutch, etc. | | | 3556 | | | | | | | 2 Engine, gears, shafts, etc. | | | 476 | | | | | | | 3 Pump, pump shaft | | | 389 | | | | | | | 4 Hull covering, 264; apron, 115; | | | | | piece behind separator, 19 | | | 398 | | | | | | | 5 Gasoline and air tanks, 167, 165; | | | | | air valve, 16 | | | 348 | | | | | | | 6 Smokestack, 310; piece to protect | | | | | midrod, 63 | | | 373 | | | | | | | 7 Float, 275; drop piece for rudder, | | | | | 57; guy-post, 18 | | | 350 | | | | | | | 8 Reel, fork and float, 128; steam | | | | | gauge with pipe, 81 | | | 209 | | | | | | | 9 Wing clamps, 200; guy-post clamps, | | | | | 32 | | | 232 | | | | | | | 10 Boiler, 800; burner, 170; counter, | | | | | 95 | | | 1065 | | | | | | | 11 Rear extension to midrod | | | 174 | | | | | | | 12 Separator and pipes to engine and | | | | | pump | | | 502 | | | | | | | 13 Exhaust pipe | | | 84 | | | | | | | 14 Front lower bearing point, 84; | | | | | clutch post, 41 | | | 125 | | | | | | | 15 Rear bearing points, 146; extra | | | | | strengtheners, 32 | | | 178 | | | | | | | 16 | | | | | | | | | | 17 Wings (without clamp) | | | 2446 | | | | | | | 18 Tail (without clamp), part of | | | | | rudder | | | | | | | | | | 19 Rudder | | | 299 | | | | | | | 20 Guy sticks, each 56 | | | 112 | | | | | | | 21 Propellers, 95 cm. wood | | | 837 | | | | | | | 22 Extra length of midrod | | | 168 | | | | | | | 23 Wood bowsprit | | | 78 | | | | | | | 24 Other things | | | | | | | | | | 25 | | | | | | | | | | 26 | | | | | | | | | | 27 Fuel (375 at starting flight) | | | 200 | | | | | | | 28 Water (2100 at starting flight) + | | | | | 616 in boiler | | | 1400 | | | | | | | 29 | | | | | | | | | | 30 | | | | | | | | | | 31 Sundries unknown | | | | | | | | | | 32 | | | | | | | | | | 33 | | | | | | | | | | 34 Total flying weight | | | | | | | | | | 35 | | | | | | | | | | 36 | | | | | | | | | | 37 | | | | | | | | | | 38 Total area of support (not | | | | | including tail) sq. ft. | | 68 | | | | | | | | 39 Total area of support in feet, | | | | | divided by total flying weight in lbs. | | | | | | | | | | 40 Total area of horizontal tail sq. | | | | | ft. | | | | | | | | | | 41 Total area of rudder (vertical) | | | | | sq. ft. | | | | | | | | | | 42 Horse-power at brake Horse-power | | | | | by formula* | | | | | | | | | | 43 | | | | | | | | | | 44 Lift at pendulum (during one | | | | | minute absolute) | | | | | | | | | | 45 Lift at pendulum (during one | | | | | minute in terms of wt.) | | | | | | | | | | 46 Minimum pressure with which wheels | | | | | turn | | | | | | | | | | 47 Position of center of pressure of | | | | | wings† | | | | | | | | | | 48 | | | | | | | | | | 49 | | | | | | | | | | 50 Curvature of wings | | | | | | | | | | 51 Root angle of wings, 10° | | | | | | | | | | 52 Tip angle of wings, 10° | | | | | | | | | | 53 Position of wings | | | | | | | | | | 54 How guyed | | | | | | | | | | 55 | | | | | | | | | | 56 | | | | | | | | | | 57 | | | | | | | | | | 58 Position of tail | | | | | | | | | | 59 Angle of tail, 5° | | | | | | | | | | 60 Co-efficient elasticity of | | | | | tail, 200 grammes at center gives | | | | | deflection to horizontal | | | | | | | | | | 61 Position of rudder | | | | | | | | | | 62 Elasticity caused by two 1/2-inch | | | | | rubber bands above and two 1/4-inch | | | | | bands, in tandem, below | | | | | | | | | | 63 Line of thrust, 1500 | | | | | | | | | | 64 Center of gravity_1 of whole | | | | | | | | | | 65 Center of gravity_2 | | | | | | | | | | 66 Center of pressure_1 of whole | | | | | estimate | | | | | | | | | | 67 Center of pressure_2 | | | | | | | | | | 68 | | | | | | | | | | 69 | | | | | | | | | | 70 | | | | | | | | | | 71 | | | | | | | | | | 72 | | | | | ---------------------------------------+----+-----+------+------+

Parts. Remarks.

1 Front end of bowsprit, 1683.5.

2 C. of float, 1614.5.

5 Front end of midrod, 1611.5.

8 C. of reel and float, 1577.5.

11 Front edge of F. W., 1609.7.

14 C. of P. on F. W., 1577.7.

17 Rear edge of F. W., 1529.7.

20 Line through center of propellers, 1500.

24 C. of G., 1498.

27 Front edge of R. W., 1406.7.

30 C. of P. on R. W., 1374.7.

33 End of midrod, 1360.3.

36 Front end of rudder, 1343.5.

39 Back edge of R. W., 1326.7.

41 Center of rudder, 1288.

44 Back end of rudder, 1229.5.

47 N. B.--Distance between C. P. on F. W., and C. G. = 79.7. Distance between C. P. on R. W. and C. G. = 123.3. If the mean C. P. is to be over the C. G. we should require an efficiency for the rear wings of 64.6%.

* H. P. = (Rev.×diam.×pitch ratio×thrust)/33000

† This is calculated on the assumption that the center of pressure on each wing or on pair of wings at a motion of 2000 feet per minute is in ordinary curved wings 2-5 the way from front to rear, that for wings of usual size the rear wings have 2-3 of the efficiency per surface of the front ones and that the tail proper bears no part of the weight; but if rear wing is smaller or larger this efficiency is smaller or larger per unit of surface.

[p305]

DATA SHEET No. 9.

Weight of Aerodrome No. 6, Flat Wings and Pénaud Rudder. Certified to by Chas. M. Manly, July 27, 1899.

---------------------------------------+----------+-------------+ Parts. | Sizes. | Weight. | ---------------------------------------+----+-----+------+------+ |‹m.›|‹ft.›|‹gr.› |‹lbs.›| 1 Frame, including everything of | | | | | metal, permanent and undetachable, | | | | | such as bed-plate, cross-rods for the | | | | | support of propellers, bearing points | | | | | for clutch. etc. | | | 2867| | | | | | | 2 Engine, gears, shafts, etc. | | | | | | | | | | 3 Pump, 123; pump shaft, 49 | | | 172| | | | | | | 4 Hull covering, including apron and | | | | | piece behind separator | | | 274| | | | | | | 5 Gasoline and air tanks, 167, 174; | | | | | air valve, 18 | | | 361| | | | | | | 6 Smokestack, 319; counter, 95; | | | | | burner, 170 | | | 584| | | | | | | 7 Float | | | 290| | | | | | | 8 Reel, fork and float | | | 128| | | | | | | 9 Wing clamps, 188; guy-post clamps, | | | | | 24 | | | 212| | | | | | | 10 Boiler, 764; steam gauge and | | | | | connections, 79 | | | 843| | | | | | | 11 Front bearing point, 75; clutch | | | | | post, 58; rear bearing points, 155 | | | 288| | | | | | | 12 Separator and pipes leading to | | | | | engine and pump | | | 502| | | | | | | 13 Drop piece and guy-post for rudder | | | 75| | | | | | | 14 | | | | | | | | | | 15 | | | | | | | | | | 16 | | | | | | | | | | 17 Wings (without clamp), repaired | | | 2123| | | | | | | 18 Tail (without clamp) | | | | | | | | | | 19 Rudder | | | 299| | | | | | | 20 Guy sticks | | | 106| | | | | | | 21 Propellers | | | 628| | | | | | | 22 Extra length of midrod | | | 377| | | | | | | 23 Wood bowsprit | | | 78| | | | | | | 24 Other things (canvas keel, 36; | | | | | rudder, 76) | | | 112| | | | | | | 25 | | | | | | | | | | 26 | | | | | | | | | | 27 Fuel (at starting flight) | | | 175| | | | | | | 28 Water (at starting flight) | | | 1525| | | | | | | 29 | | | | | | | | | | 30 | | | | | | | | | | 31 Sundries unknown | | | | | | | | | | 32 | | | | | | | | | | 33 | | | | | | | | | | 34 Total flying weight | | |12,019| | | | | | | 35 | | | | | | | | | | 36 | | | | | | | | | | 37 | | | | | | | | | | 38 Total area of support (not | | | | | including tail) sq. ft. | |54 | | | | | | | | 39 Total area of support in feet, | | | | | divided by total flying | | | | | weight in lbs | | | | | | | | | | 40 Total area of horizontal tail sq. | | | | | ft. | | 9.5 | | | | | | | | 41 Total area of rudder (vertical) | | | | | sq. ft. | | 7.75| | | | | | | | 42 Horse-power at brake Horse-power | | | | | by formula* | | | | | | | | | | 43 | | | | | | | | | | 44 Lift at pendulum (during one | | | | | minute absolute) | | | | | | | | | | 45 Lift at pendulum (during one | | | | | minute in terms of wt.) | | | | | | | | | | 46 Minimum pressure with which wheels | | | | | turn | | | | | | | | | | 47 Position of center of pressure of | | | | | wings† | | | | | | | | | | 48 | | | | | | | | | | 49 | | | | | | | | | | 50 Curvature of wings, 1 in 18 | | | | | | | | | | 51 Root angle of wings, 10° | | | | | | | | | | 52 Tip angle of wings 10° | | | | | | | | | | 53 Position of wings. | | | | | | | | | | 54 How guyed. | | | | | | | | | | 55 | | | | | | | | | | 56 | | | | | | | | | | 57 | | | | | | | | | | 58 Position of tail | | | | | | | | | | 59 Angle of tail, 5° | | | | | | | | | | 60 Co-efficient elasticity of tail, | | | | | 200 grammes at center to deflect it | | | | | to the horizontal | | | | | | | | | | 61 Position of rudder | | | | | | | | | | 62 | | | | | | | | | | 63 Line of thrust, 1500 | | | | | | | | | | 64 Center of gravity_1 of whole | | | | | | | | | | 65 Center of gravity_2 | | | | | | | | | | 66 Center of pressure_1 of whole | | | | | estimate | | | | | | | | | | 67 Center of pressure_2 | | | | | | | | | | 68 | | | | | | | | | | 69 | | | | | | | | | | 70 | | | | | | | | | | 71 | | | | | | | | | | 72 | | | | | ---------------------------------------+----+-----+------+------+

Parts. Remarks.

1 Front end of bowsprit, 1695.7. Weight 2867 includes Parts 2.

2 Front end of midrod, 1623.7.

5 C. of float, 1618.2.

8 Reel and float, 1576.7.

11 Front edge, F. W., 1595.8.

13 C. of P. on F. W., 1563.8.

16 Rear edge F. W., 1515.8.

19 Line through center of propellers, 1500.

23 C. of G., 1485.5.

26 Front edge of R. W., 1406.7.

29 C. of P. on R. W., 1374.7.

32 End of midrod, 1352.2.

35 Front end of rudder, 1333.9.

38 Rear edge of R. W., 1326.7.

40 Center of rudder, 1280.6.

43 Back end of rudder, 1219.9.

* H. P. = (Rev.×diam.×pitch ratio×thrust)/33000

† This is calculated on the assumption that the center of pressure on each wing or on pair of wings at a motion of 2000 feet per minute is in ordinary curved wings 2-5 the way from front to rear, that for wings of usual size the rear wings have 2-3 of the efficiency per surface of the front ones and that the tail proper bears no part of the weight; but if the rear wing is smaller or larger this efficiency is smaller or larger per unit of surface.

[p306]

DATA SHEET No. 10.

Weight of Aerodrome No. 5, Flat Wings and Pénaud Rudder. Certified to by Chas. M. Manly, July 27, 1899.

---------------------------------------+-------------+-------------+ Parts. | Sizes. | Weight. | ---------------------------------------+----+--------+------+------+ |‹m.›| ‹ft.› |‹gr.› |‹lbs.›| 1 Frame, including everything of | | | | | metal, permanent and undetachable, | | | | | such as bed-plate, cross-rods for the | | | | | support of propellers, gears, shafts, | | | | | etc. (such as guy-wires and turn | | | | | buckles, 26g). | | | 3342| | | | | | | 2 Engine. | | | 476| | | | | | | 3 Pump, 301; pump shaft, 55; support | | | | | to pump, 33. | | | 389| | | | | | | 4 Hull covering: front, 47; sides, | | | | | 92; top 46; small side pieces, 44. | | | 229| | | | | | | 5 Gasoline and air tanks, 167, 165; | | | | | air valve, 18; netting, 30; piece | | | | | rear of separator, 20. | | | 400| | | | | | | 6 Smokestack, 310; piece to protect | | | | | midrod, 63. | | | 373| | | | | | | 7 Float, 290; drop piece for rudder, | | | | | 57. | | | 347| | | | | | | 8 Reel, fork and float, 128; counter, | | | | | 95. | | | 223| | | | | | | 9 Wing clamps, 202; guy-post clamps, | | | | | 33. | | | 235| | | | | | | 10 Burner, 170; boiler 759. | | | 929| | | | | | | 11 Separator with tubes brazed to it. | | | 513| | | | | | | 12 Steam pipe, 87; steam gauge and | | | | | connections, 81. | | | 168| | | | | | | 13 Exhaust pipe, 90; wooden plugs in | | | | | nose of frame, 10 | | | 100| | | | | | | 14 Upper front bearing point and | | | | | clutch post. | | | 136| | | | | | | 15 Lower front bearing point, 84; | | | | | lower rear bearing point, 146; | | | | | clutch, 41. | | | 271| | | | | | | 16 | | | | | | | | | | 17 Wings (without clamp), front, | | | | | 2×662; rear 2×605. | | | 2534| | | | | | | 18 Tail (without clamp). | | | | | | | | | | 19 Rudder. | | | 299| | | | | | | 20 Guy sticks 65; rear, 50. | | | 114| | | | | | | 21 Propellers, 100 cm. round ends, | | | | | 30° blade. | | | 757| | | | | | | 22 Extra length of midrod, front, | | | | | 174; rear, 227. | | | 401| | | | | | | 23 Wood bowsprit (heavy one). | | | 130| | | | | | | 24 Other things. | | | | | | | | | | 25 | | | | | | | | | | 26 | | | | | | | | | | 27 Fuel (390 at starting flight). | | | 225| | | | | | | 28 Water (2000 at starting flight). | | | 1500| | | | | | | 29 | | | | | | | | | | 30 Lead on bowsprit to balance. | | | 13| | | | | | | 31 Sundries unknown. | | | | | | | | | | 32 | | | | | | | | | | 33 | | | | | | | | | | 34 Total flying weight. | | |14,704| 1 03 | | | | | | 35 | | | | | | | | | | 36 | | | | | | | | | | 37 | | | | | | | | | | 38 Total area of support (not | | | | | including tail). sq. ft. | |68 | | | | | | | | 39 Total area of support in feet, | | | | | divided by total flying weight in lbs. | | 2.1935 | | | | | | | | 40 Total area of horizontal tail. sq. | | | | | ft. | | 6.94 | | | | | | | | 41 Total area of rudder (vertical). | | | | | sq. ft. | | 7.64 | | | | | | | | 42 Horse-power at brake Horse-power | | | | | by formula* | | | | | | | | | | 43 | | | | | | | | | | 44 Lift at pendulum (during one | | | | | minute absolute). | | | | | | | | | | 45 Lift at pendulum (during one | | | | | minute in terms of wt.). | | | | | | | | | | 46 Minimum pressure with which wheels | | | | | turn. | | | | | | | | | | 47 Position of center of pressure of | | | | | wings†. | | | | | | | | | | 48 | | | | | | | | | | 49 | | | | | | | | | | 50 Curvature of wings, 1 in 12, but | | | | | about 1 in 11 now. | | | | | | | | | | 51 Root angle of wings, 10°. | | | | | | | | | | 52 Tip angle of wings 10°. | | | | | | | | | | 53 Position of wings. | | | | | | | | | | 54 How guyed. | | | | | | | | | | 55 | | | | | | | | | | 56 | | | | | | | | | | 57 | | | | | | | | | | 58 Position of tail. | | | | | | | | | | 59 Angle of tail, 5° elevation at | | | | | rear end. | | | | | | | | | | 60 Co-efficient elasticity of tail, | | | | | 200 grammes at center to deflect it | | | | | to a horizontal. | | | | | | | | | | 61 Position of rudder. | | | | | | | | | | 62 | | | | | | | | | | 63 Line of thrust, 1500. | | | | | | | | | | 64 Center of gravity_1 of whole, 1498. | | | | | | | | | | 65 Center of gravity_2. | | | | | | | | | | 66 Center of pressure_1 of whole | | | | | estimate. | | | | | | | | | | 67 Center of pressure_2. | | | | | | | | | | 68 | | | | | | | | | | 69 | | | | | | | | | | 70 | | | | | | | | | | 71 | | | | | | | | | | 72 | | | | | ---------------------------------------+----+--------+------+------+

Parts. Remarks.

1 13 grammes of lead on end of bowsprit.

2 End of bowsprit, 1708.

4 C. of float, 1622.

6 Front end of midrod, 1619.

9 Reel and float, 1601.5.

12 Front edge of F. W., 1609.7.

15 C. of P. on F. W., 1577.7.

17 Rear edge of F. W., 1529.7.

20 Line through center of propellers, 1500

24 C. of G., 1498.

27 Front edge of R. W., 1404.7.

30 C. of P. on R. W., 1372.7.

33 End of midrod, 1350.3.

36 Front end of rudder, 1333.5.

39 Back edge of R. W., 1324.7.

41 Centre of rudder, 1279.5.

44 Rear end of rudder, 1222.

47 Distance between C. P. on F. W. and C. G., = 79.7. Distance between C. P. on R. W., and C. G. = 125.3. If the mean C. P. is to be over the C. G. we should require an efficiency of 63.6 for the rear wings.

* H. P. = (Rev.×diam.×pitch ratio×thrust)/33000

† This is calculated on the assumption that the center of pressure on each wing or on pair of wings at a motion of 2000 feet per minute is in ordinary curved wings 2-5 the way from front to rear, that for wings of usual size the rear wings have 2-3 of the efficiency per surface of the front ones and that the tail proper bears no part of the weight: but if the rear wing is smaller or larger this efficiency is smaller or larger per unit of surface.

[p307]

DATA SHEET No. 11.

Weight of Aerodrome No. 5, Superposed Wings and Pénaud Rudder. Certified to by Chas. M. Manly, August 3, 1899.

---------------------------------------+----------+-------------+ Parts. | Sizes. | Weight. | ---------------------------------------+----+-----+------+------+ |‹m.›|‹ft.›|‹gr.› |‹lbs.›| 1 Frame, including everything of | | | | | metal, permanent and undetachable, | | | | | such as bed-plate, cross-rods for the | | | | | support of propellers, bearing points | | | | | for clutch, etc. | | | 3556| | | | | | | 2 Engine, complete | | | 476| | | | | | | 3 Pump, 301; pump shaft, 55; support | | | | | to pump, 33 | | | 389| | | | | | | 4 Hull covering, 276; apron, 117; | | | | | piece behind separator | | | 393| | | | | | | 5 Gasoline and air tanks, 167, 165; | | | | | air valve, 17 | | | 349| | | | | | | 6 Smokestack and piece to protect | | | | | midrod | | | 385| | | | | | | 7 Float, 290; drop piece for rudder, | | | | | 57; guy-post and clamp, 17 | | | 364| | | | | | | 8 Reel, fork and float, 128; steam | | | | | gauge with pipe, 81 | | | 209| | | | | | | 9 Wing claps, 202; guy-post clamps, 33 | | | 235| | | | | | | 10 Boiler, 775; burner, 171; counter, | | | | | 100 | | | 1046| | | | | | | 11 Rear extension to midrod | | | 227| | | | | | | 12 Separator and pipes to engine and | | | | | pump | | | 513| | | | | | | 13 Exhaust pipe | | | 90| | | | | | | 14 Front lower bearing points, 84; | | | | | clutch post, 41 | | | 125| | | | | | | 15 Rear bearing points, 146; extra | | | | | strengtheners, 32 | | | 178| | | | | | | 16 | | | | | | | | | | 17 Wings (without clamp) | | | | | | | | | | 18 Tail (without clamp), part of | | | | | rudder | | | | | | | | | | 19 Rudder | | | 309| | | | | | | 20 Guy sticks, each 60 | | | 120| | | | | | | 21 Propellers, 100 cm. round end | | | 757| | | | | | | 22 Extra length of midrod, front | | | 174| | | | | | | 23 Wood bowsprit | | | 130| | | | | | | 24 Other things, 248 grammes of lead | | | | | on end of bowsprit | | | 248| | | | | | | 25 | | | | | | | | | | 26 | | | | | | | | | | 27 Fuel (at starting flight) | | | | | | | | | | 28 Water (at starting flight) | | | | | | | | | | 29 | | | | | | | | | | 30 | | | | | | | | | | 31 Sundries unknown | | | | | | | | | | 32 | | | | | | | | | | 33 | | | | | | | | | | 34 Total flying weight | | |14,354| | | | | | | 35 | | | | | | | | | | 36 | | | | | | | | | | 37 | | | | | | | | | | 38 Total area of support (not | | | | | including tail) sq. ft. | |87.5 | | | | | | | | 39 Total area of support in feet, | | | | | divided by total flying weight in lbs. | | 2.75| | | | | | | | 40 Total area of horizontal tail sq. | | | | | ft. | | 6.94| | | | | | | | 41 Total area of rudder (vertical) | | | | | sq. ft. | | 7.64| | | | | | | | 42 Horse-power at brake Horse-power | | | | | by formula* | | | | | | | | | | 43 | | | | | | | | | | 44 Lift at pendulum (during one | | | | | minute absolute) | | | | | | | | | | 45 Lift at pendulum (during one | | | | | minute in terms of wt.) | | | | | | | | | | 46 Minimum pressure with which wheels | | | | | turn | | | | | | | | | | 47 Position of center of pressure of | | | | | wings† | | | | | | | | | | 48 | | | | | | | | | | 49 | | | | | | | | | | 50 Curvature of wings, 1 in 11 | | | | | | | | | | 51 Root angle of wings, 10° | | | | | | | | | | 52 Tip angle of wings, 10° | | | | | | | | | | 53 Position of wings | | | | | | | | | | 54 How guyed | | | | | | | | | | 55 | | | | | | | | | | 56 | | | | | | | | | | 57 | | | | | | | | | | 58 Position of tail | | | | | | | | | | 59 Angle of tail | | | | | | | | | | 60 Co-efficient elasticity of | | | | | tail, 200 grammes at center gives | | | | | deflection of 5° | | | | | | | | | | 61 Position rudder | | | | | | | | | | 62 Elasticity caused by rubber bands | | | | | | | | | | 63 Line of thrust, 1500 | | | | | | | | | | 64 Center of gravity_1 of whole | | | | | | | | | | 65 Center of gravity_2 | | | | | | | | | | 66 Center of pressure_1 of whole | | | | | estimate | | | | | | | | | | 67 Center of pressure_2 | | | | | | | | | | 68 | | | | | | | | | | 69 | | | | | | | | | | 70 | | | | | | | | | | 71 | | | | | | | | | | 72 | | | | | ---------------------------------------+----+-----+------+------+

Parts. Remarks.

1 C. P. on F. W., 1577.7.

2 Line through center of propellers, 1500.

6 C. of G., 1498.

8 C. P. on R. W., 1372.7.

* H. P. = (Rev.×diam.×pitch ratio×thrust) / 33000

† This is calculated on the assumption that the center of pressure on each wing or on pair of wings at a motion of 2000 feet per minute is in ordinary curved wings 2-5 the way from front to rear, that for wings of usual size the rear wings have 2-3 of the efficiency per surface of the front ones and that the tail proper bears no part of the weight; but if rear wing is smaller or larger this efficiency is smaller or larger per unit of surface.

[p308]

DATA SHEET No. 12.

Weight of Aerodrome, One-Quarter Model. Certified to by Chas. M. Manly, June 11, 1901.

---------------------------------------+----------+-------------+ Parts. | Sizes. | Weight. | ---------------------------------------+----+-----+------+------+ |‹m.›|‹ft.›|‹gr.› |‹lbs.›| 1 Frame, including everything of | | | | | metal, permanent and undetachable, | | | | | such as bed-plate, cross-rods for the | | | | | support of propellers, bearing points | | | | | for clutch, etc. | | | 3245| | | | | | | 2 Engine, bed plates and sparkers | | | 4549| 10 | | | | | | 3 Gears, shafts, etc. | | | 1662| | | | | | | 4 | | | | | | | | | | 5 | | | | | | | | | | 6 | | | | | | | | | | 7 Floats, front, 212; rear, 220 | | | 432| | | | | | | 8 Reel, float and cord, 142 | | | 142| | | | | | | 9 Wing clamps, 86 and 97; rudder | | | | | clamp and post | | | 183| | | | | | | 10 Carburetor and fuel | | | 737| | | | | | | 11 Spark coil, 1512; holders, 110 | | | 1622| | | | | | | 12 Battery | | | 1627| | | | | | | 13 Primary connections | | | | | | | | | | 14 Secondary connections | | | | | | | | | | 15 Guy-post clamps, each 13 | | | 26| | | | | | | 16 | | | | | | | | | | 17 Wings (without clamp), new flat | | | | | wings | | | 2634| | | | | | | 18 Tail (without clamp), Pénaud rudder | | | 353| | | | | | | 19 Rudder, wind vane | | | 88| | | | | | | 20 Guy sticks | | | 30| | | | | | | 21 Propellers, 585 each | | | 1170| | | | | | | 22 Extra length of midrod, front, | | | | | 125; rear, 225 | | | 350| | | | | | | 23 Wood bowsprit | | | 75| | | | | | | 24 Other Things | | | | | | | | | | 25 Counter | | | 110| | | | | | | 26 Guy-post clamp and post for rudder | | | 16| | | | | | | 27 | | | | | | | | | | 28 | | | | | | | | | | 29 Drop piece for rudder | | | 53| | | | | | | 30 | | | | | | | | | | 31 Sundries unknown | | | | | | | | | | 32 | | | | | | | | | | 33 | | | | | | | | | | 34 Total flying weight | | |19,104| | | | | | | 35 | | | | | | | | | | 36 | | | | | | | | | | 37 | | | | | | | | | | 38 Total area of support (not | | | | | including tail) sq. ft. | |61.41| | | | | | | | 39 Total area of support in feet, | | | | | divided by total flying weight in lbs. | | 1.46| | | | | | | | 40 Total area of horizontal tail sq. | | | | | ft. | | 6 | | | | | | | | 41 Total area of rudder (vertical) | | | | | sq. ft. | | 6 | | | | | | | | 42 Horse-power at brake 1.5 at 750 R. | | | | | P. M. | | | | | | | | | | 43 Engine gave 2.01 H. P. on brake at | | | | | 900 R. P. M. | | | | | | | | | | 44 Lift at pendulum (during one | | | | | minute absolute) | | | | | | | | | | 45 Lift at pendulum (during one | | | | | minute in terms of wt.) | | | | | | | | | | 46 Minimum pressure with which wheels | | | | | turn | | | | | | | | | | 47 Position of center of pressure of | | | | | wings† | | | | | | | | | | 48 | | | | | | | | | | 49 | | | | | | | | | | 50 Curvature of wings, 1 in 20-1/2 | | | | | | | | | | 51 Root angle of wings, 10° | | | | | | | | | | 52 Tip angle of wings, 10° | | | | | | | | | | 53 Position of wings: C. P. F. W., | | | | | 157.82; C. P. R. W., 1386.9 | | | | | | | | | | 54 How guyed | | | | | | | | | | 55 Position of tail | | | | | | | | | | 56 Angle of tail, 5° | | | | | | | | | | 57 Co-efficient elasticity of tail, | | | | | 200 at center depresses to horizontal | | | | | | | | | | 58 Position of rudder (center), 1292.9 | | | | | | | | | | 59 | | | | | | | | | | 60 Line of thrust, 1500, through | | | | | center of propellers | | | | | | | | | | 61 Center of gravity_1 of whole, | | | | | 1503.7 | | | | | | | | | | 62 Center of gravity_2, 2497.5 | | | | | | | | | | 63 Center of pressure_1 of whole | | | | | estimate, 1503.7 | | | | | | | | | | 64 Center of pressure_2, 2513.2 | | | | | | | | | | 65 Center of clutch post, 1515.4 | | | | | | | | | | 66 Center of coil, 1555.3 | | | | | | | | | | 67 Center front float, 16.45 | | | | | | | | | | 68 Center rear float, 1372.6 | | | | | | | | | | 69 Center wind vane rudder, 1435.6 | | | | | | | | | | 70 Center Pénaud rudder, 1292.9 | | | | | | | | | | 71 Rear end Pénaud rudder, 1215.9 | | | | | | | | | | 72 Front end of Bowsprit, 1707.2 | | | | | ---------------------------------------+----+-----+------+------+

* H.P. = (Rev.×diam.×pitch ratio×thrust) / 33000

† This is calculated on the assumption that the center of pressure on each wing or on pair of wings at a motion of 2000 feet per minute is in ordinary curved wings 2-5 the way from front to rear, that for wings of usual size the rear wing have 2-3 of the efficiency per surface of the front ones and that the tail proper bears no part of the weight; but if rear wing is smaller or larger this efficiency is smaller or larger per unit of surface.

[p309]

INDEX

A

Abbreviations and symbols for points on aerodrome … 14, 15

Accidents, in launching large aerodrome … 126, 184, 185, 265–281

― loss of model aerodrome … 17, 94, 154

Aeolipiles, alcohol … 55, 56, 59, 60, 65, 66, 112

Aerial navigation, report of Board of Ordnance on … 276, 279

Aerodrome, balancing of … 45–52, 81, 90, 109, 134, 211, 212

― construction of … 53–80, 164–187, 234–250

― definition of word … iii

― dimensions of (‹see› aerodrome models and data sheets).

― eighth-size model … 133, 134, 154

― engines (‹see› engines and motors).

― experiments with models … 6–14, 16–24, 133–155

― field trials (‹see› trials).

― first flight of model, May 6, 1896 … 2, 3, 107, 108, 117

― first trial of a “flying machine” in free air … 97

― flight (‹see also› trials).

― ― first model, May 6, 1896 … 2, 3, 107, 117

― ― large machine (1903) … 126, 127, 255–282

― ― photographs of … 108, 259, 260

― large … 126, 127, 129, 130, 156, 183, 225, 255–282

― ― construction of … 164–187, 234–250

― ― launching apparatus for … 156–163, 183

― ― shop tests … 251–254

― ― trials (1903) … 126, 181, 255–282

― ― weight of … 277

― launching apparatus for models … 92–122, 133, 134

― ― ― ― large aerodrome … 156–163, 183

― man-carrying (‹see also› aerodrome large) … 123, 125, 129, 130, 151, 153, 156–187, 234–250, 255, 282.

― model, descriptions of (‹see also› data sheets).

― ― ― ― No. 0 … 21, 30, 31, 36, 38, 40, 53, 55, 75

― ― ― ― Nos. 1, 2, 3 … 28, 29, 38, 40, 53

― ― ― ― No. 4 … 53, 62–67, 69, 70, 72, 75–79, 81–83, 86, 92–109, 120

― ― ― ― No. 5 … 26, 64–66, 69, 70, 75–79, 81, 82–84, 86, 88, 89, 90, 92–109, 110–122, 130, 131, 134, 135–155, 158, 174, 188, 189, 208–210, 231, 257, 281.

― ― ― ― No. 6 … 49, 61, 62, 78–81, 89, 90, 92–109, 110–122, 130, 131, 134, 158, 174, 188, 193, 208, 210, 231, 257, 281.

― ― ― ― rubber pull … 11–20

― ― eighth-size … 133, 134, 154

― ― frames of … 39, 53–80, 90, 112, 119, 129

― ― launching apparatus for … 92–112, 134

― ― quarter-size … 158, 159, 170, 226–233, 234, 255, 257–261, 281

― ― results from … 17, 129

― ― steam driven (‹see also› Nos. 5, 6) … 122, 164, 165, 224, 281

― ― trials, of Nos. 0, 1, 2, 3 (1892) … 29, 53

― ― ― ― Nos. 4, 5, 6 (1893) … 63, 92–106

― ― ― ― Nos. 5, 6 (1896) … 2, 79, 106–109

― ― ― ― No. 6 (1898) … 61

― ― ― ― Nos. 5, 6 (1899) … 49, 79, 135–155, 231, 257

― ― ― ― Nos. 30, 31, and others … 6–14, 17, 19

― motors (‹see› engines and motors).

― quarter-size models (‹see› aerodrome models).

― rubber-power models … 5, 8–24, 44

― weights of (‹see› weight and data sheets).

Aerodromics, science of … iii, 7

Aerodynamics … 7, 30, 43, 44, 80, 91, 99

― experiments in … 1, 6, 7, 19, 21, 32, 41, 80, 98, 128, 150, 153

Aeronaut (‹see also› aviator) … 130

Air, compressed … 11, 24, 25, 26, 68, 112

― liquid … 154

― resistance of … 6, 8, 9, 142, 165–167

Air-chamber … 64, 68, 69, 98, 112, 113

Air-cooled engine … 226

Alcohol and hydrocarbons, use of, as fuel … 24, 25, 35, 55, 57, 66, 72, 73

Alcohol aeolipiles … 55, 56, 60, 66, 69, 112

Allegheny Observatory, experiments at … 11, 13, 31, 150

Allotment, Government, for man-carrying aerodrome … 124–126, 132, 278

Aluminum-bronze, use of … 114, 116, 173, 174

Aluminum in engine construction … 32, 114, 243, 252

― sheathing of hull … 69

― wires … 84

Aneroid barometer for determining height … 186

Anemometer cups … 143

Angle, diedral, of wings … 45, 82, 89

― of inclination … 41, 43, 83, 99, 100

― ― rotation … 61

― ― wings, root angle … 83, 89, 91, 97, 98, 100, 101, 103

Area, relation to weight and power … 43, 44, 64, 90, 99, 101

― supporting (‹see also› surface) … 82, 87–89, 91, 93

Asbestos, use of … 35, 63, 67

Associated Press statement to … 266, 280

Aviator, equilibrium of … 161, 169, 253

― weight of … 130, 210, 256

Aviator’s car … 185–187, 214, 251, 252

― jacket … 273

― seat … 185

― wheel … 214, 216, 265, 266, 272

B

Bagging or pocketing of wings … 84, 86, 100, 195, 203

Balance (‹see also› equilibrium) … 82, 165

Balancing of aerodrome … 45–52, 81, 90, 109, 134, 211, 258

― ― engine … 246, 247

― ― wings and rudder … 211, 255

Ball-bearings on launching car … 160, 175, 177, 252, 253

Bamboo ribs for wings … 200

Barometer, aneroid … 186

Barus, Dr Carl, boiler experiments by … 58, 70–75, 93–95

Batteries, electric … 11, 24, 26, 27, 162, 212, 220–222, 237, 240, 241, 257, 262, 263

Bearings, ball, on aerodrome and launching car … 160, 175, 177, 252, 253

― bronze, on model aerodromes … 177

Bedplates … 116, 168, 175, 273

“Beehive” boilers (‹see› boilers).

Bell Alexander Graham … 4, 96, 102–104, 106, 108

Bessemer steel guy wires … 172

Bevel gears … 174, 177, 241

Bird-wings, construction of … 7, 188, 200, 201

Birds, soaring, study of … 7, 9, 88, 287

Blazer, S. M., engineer … 126

“Bleeder,” feed tube for burner … 67, 113

Blériot aeroplane of Langley type … 283

Blower for artificial wind … 61, 97, 225

Board of Ordnance and Fortification … 124, 126, 132, 250, 255, 271, 276, 278, 279, 280

Boat, house … 92, 93, 136, 148, 149, 156–163, 269

Body, construction of (‹see also› hull) … 32, 60

Boiler, “Beehive” type … 34, 39

― coil of … 34–39, 70, 71, 113–116

― development of … 55–59, 65, 68, 70–75, 102, 114–116

― pressure … 58, 59, 63, 68, 69, 101, 102

― report on, by Dr. Barus … 70–75

― serpollet type … 56, 57

― spray type … 70

― tests of … 70–75, 135

― tubing of … 70–75, 114, 141

― water-tube type of … 34, 35, 70–75, 114

Bolometer, development of … 123

Brake, horse-power … 28, 37, 58, 61, 64–69, 117, 223, 224, 230, 233

― Prony … 38, 61, 65, 66, 117, 179, 222, 228, 233, 249

Brass, use of … 54, 63, 113, 180

Brazing … 117, 173, 175, 235, 236

Bronze, aluminum … 114, 116, 171, 173, 177, 234, 237–240

Burners, Bunsen type … 35, 68, 72, 113

― gasoline … 56, 60, 61, 62, 65, 67, 68, 70–75, 112–116, 149

― shield for … 60, 67, 95, 115

Bushing, cast-iron … 114–117, 121

Buzzard, American, and “John Crow,” study of … 285

C

Cameras, telephoto … 260, 261, 273

“Canvas-covered” propellers … 84, 178

Car, aviator’s … 185–187, 214, 251, 252

― launching (‹see› launching apparatus).

Carbon, energy developed by the use of … 27

Carbonic-acid gas as motive power … 11, 24, 26, 28, 29, 39, 53, 54

― liquid … 24, 28

― ― freezing of … 28–29

― ― latent heat of … 28

Carburetor, development of, suitable type of … 224, 225, 239, 240, 248, 249, 251, 253, 259

Carpenter, Frank G., witnesses flights … 108

Cast-iron, use of (‹see also› iron) … 114–117, 121, 234–236, 240

“Cast-off” apparatus … 96, 110

Center of gravity … 10, 13–16, 45–52, 61, 64, 80, 91, 103, 143, 144, 150, 209, 210

― ― ― in relation to pressure … 10, 11, 15, 46, 48, 64, 98, 99, 101, 103

― ― pressure … 7, 10, 11, 13, 15, 45–52, 78, 80, 84, 87, 88, 90, 91, 200, 209, 210

― ― ― formulæ for … 49, 87, 88, 90

― ― wings and tail … 16

― ― rotation … 62

― ― thrust … 62

Centrifugal pump … 241, 248

Charcoal, as fuel … 57

China silk (‹see› silk).

Chopawamsic Island, Potomac River … 93, 135, 153, 183, 256

Chronograph attachments … 162, 163, 229

Circulating pump … 114, 244

Clamps, wing … 82, 89, 145, 183

Coast and Geodetic Survey … 93, 145, 256

Coefficient of elasticity … 146

Coil, spark (‹see› sparking devices).

Compressed air … 24, 25–26, 68, 112, 113

Condenser, steam … 65

Construction and tests of large engine … 234–250

Construction of frame and engines … 53–80

― ― ― of large aerodrome … 164–187

― ― supporting surfaces … 188–206

Control, equilibrium and … 77, 78, 119, 207–217

― gyroscopic … 78, 211

Cooling systems, (‹see› water and air cooling).

Copper, use of … 27, 39, 63, 72, 112–115, 162

Copper tubing … 35, 56, 57, 59, 112, 115, 140, 141, 248

Counter, speed … 62, 120, 185, 243, 249

― ― propellers … 178

Covering for tail … 86, 103

― ― wings … 54, 63, 77, 81, 86, 88, 90, 148, 194, 195, 205

Crank bell … 110

― starting … 244

Crank-pin … 237–239, 243–247

Crank-shaft … 237, 239, 244–246, 250

Cube, law of the … 129, 130, 222, 244, 249

Currie, Rolla P., report on American Buzzard … 289

Curved surfaces (‹see also› wing curvature) … 18, 44, 47, 99

Cylinders (‹see also› engines, cylinders).

― aluminum in construction of … 114

― brass in construction of … 54

― steel tubes in … 116, 121, 234, 235, 239, 240

― construction of … 112, 114, 116, 121, 212, 213, 232, 235, 239, 240, 246

― five, engine … 245, 246, 250, 255

― high-pressure … 33

― low-pressure … 33

― multiple, engine … 226

― oscillating … 33, 38

― tests of (‹see also› engine tests) … 55

― walls of … 239

― weight of … 246, 247, 250

D

Daniell, on energy in storage batteries … 27

Data sheets … 297

Definitions of terms and symbols … 14, 15

Deflection, absence of … 269

de Lucy, on sustaining surfaces … 19

Diedral angle of wings … 45, 82, 83, 85, 89, 96, 146

Dimensions (‹see› aerodrome descriptions and data sheets).

Distance of flights … 103, 107–109, 135–155, 258

Distortion of wings … 82–84, 91, 98, 105

Dry batteries … 262

Duration of flights (‹see also› time) … 103, 107, 108, 137, 145, 148, 258

Dynamometer, use of … 222, 228, 229, 230, 242, 247, 249

E

Eagle quill and spruce rib, comparative strength of … 201

Early steam motors and other models … 30–40

Efficiency of wings … 87, 89, 91, 144, 192, 193

Eighth-size models … 133, 134, 154

Elastic limit of rubber … 9, 22, 23

Elasticity of tail … 78, 90, 144, 152

― coefficient of … 51, 144, 146

Electric batteries … 24, 26, 27, 212, 262, 263

― circuits … 70, 212, 220–223, 237, 241, 257

Electricity as motive power … 24, 26–28

Energy in foot pounds (‹see also› lift) … 23–27

Engine (‹see also› motors) … 112–116, 179, 180, 222–225, 226–233, 234–250, 281

― American builders … 131, 180, 219, 228

― air-cooled … 226

― automobile … 219

― balancing of … 246, 247

― carbonic-acid gas … 24, 26–29

― compressed air … 11, 24–26, 68, 112

― construction of, and frames … 53–79, 114, 116, 219, 223–233

― ― ― ― tests … 234–250

― contract for … 126

― cylinders of … 33, 38, 54, 112, 114–116, 121, 212, 213, 232, 235–239, 246, 250, 255

― description of one-horse-power … 37, 116

― electric … 24, 26–28

― European builders … 131, 140, 219, 234

― experimental … 218–225

― five-cylinder … 224, 232, 234–250, 255

― gas (‹see also› gasoline) … 26, 28, 131, 133

― gasoline … 24, 37, 65, 125, 131, 179, 210, 218, 219, 224, 277

― gunpowder … 24, 25

― horse-power (‹see also› brake, horse-power) … 37, 58, 116, 233

― hot-water … 24, 25, 68

― large, construction and tests of … 133, 234–250, 281, 282

― ― weight of … 247, 250, 256

― Manly … 219–225

― multiple cylinder … 226

― oscillating … 33, 38

― radiator … 252

― steam … 24, 30–40, 64, 69, 116, 120

― ― dimensions of … 116

― Stringfellow … 30, 31

― tests … 37, 55, 61, 69, 102, 133, 148, 234–250, 281, 282

― water-cooled … 220, 235, 236, 241, 247, 248, 252

― weight of … 116, 126, 130, 209, 247, 250

Equilibrium, maintenance of … 6, 31, 45, 51, 144, 213–216

― of aviator … 161, 169, 213, 253

― and control … 77, 78, 119, 207–217

― lateral, and longitudinal stability … 31, 45–52

Evaporation, rate of gasoline … 65, 66

Evaporators … 37, 65, 67, 114, 148

F

“Factor of safety” … 111, 186

Feathers, pliability of … 188, 200

― toy-propeller, blades made of … 8

Feed, gravity … 239

Fibre insulation … 241, 257

Field trials, eighth-size … 133, 134, 154

― ― large and quarto size models … 126, 158, 170, 181, 226–234, 255–282

― ― models Nos. 0, 1, 2, 3 … 29, 53

― ― ― Nos. 4, 5, 6 … 63, 92–106

― ― ― Nos. 5, 6, 2 … 61, 79, 135–155, 231, 257

Fire-proofing preparation … 148

First flight of heavier than air machine … 107, 108

First trial of a flying-machine in free air … 97

Flexure of wings … 82–84, 91, 98, 105

Flight (‹see› aerodrome and aerodrome model flights).

― bird, study of … 7

― of large machine … 126, 181, 255–282

― ― May 6, 1896 … 2, 3, 107–108

― ― models Nos. 4, 5, 6 … 2, 63, 79, 92–109, 135–155

― ― quarter size model … 259

― ― rubber-driven models … 16–20

― ― quarter-size models … 158, 170, 226–233, 243, 255, 257–261, 281

Floating the models … 64, 68, 69, 99, 103, 119, 120

Fly-wheels of engine … 242, 243, 247, 252

Flying aerodrome model as a kite … 133, 154, 155

Flying-weight of aerodromes (‹see also› data sheets) … 15, 62, 63, 76, 77, 81, 89, 91, 148, 247, 250, 256

Foot-pounds, definition of … 15

― energy in (‹see also› horse-power) … 22, 27, 62

Force-pump … 57

Formulæ:

― area … 19

― center of pressure … 49, 87, 88, 90, 101

― drift … 41, 43

― efficiency … 47

― Harting’s … 19

― horse-power … 15, 62

― lift or weight … 41, 43, 62

― Manly’s, for changing center of pressure … 51

― Maxim’s, for horse-power … 15

― resistance … 41

― soaring speed … 91

― tandem wing … 87

― work (‹see also› horse-power) … 18, 23, 27, 62

Frame, construction of, model … 39, 53–80, 90, 112, 119, 129

― ― ― large aerodrome … 164–187, 253

― main … 165–168, 170

― resistance of … 165–167

― testing of … 79

― transverse … 77, 165, 174–178

― work … 118

French academy, communication to … 3

Fuel, alcohol and hydrocarbon … 24, 25, 35, 55, 57, 66, 72, 73

― carbon … 27

― carbonic acid gas … 11, 24, 26, 28, 29, 39, 53, 54

― charcoal … 57

― gas … 26, 28, 37

― gasoline … 24, 25, 36, 37, 65–68, 112, 125, 224, 248, 259

― quantity of … 68

Fuel-tank … 36, 65, 67, 68, 112, 113

Funds for experiments … 124–126, 132, 257, 278, 279, 281

G

Gaertner, Mr., instrument maker … 93, 95

Gas, carbonic-acid … 24, 26, 28, 36, 68, 113

Gas-burners … 35, 55, 60, 65, 70–75, 112, 113

Gas-engine (‹see also› engines, gas and gasoline) … 26, 28, 37

― Five cylinder … 224, 234–250, 255

― large … 234–250, 277

― model … 26–28, 65, 131, 133, 232–234

Gasoline-burners … 56, 60, 62, 65, 67, 68, 70–75, 112–116, 149

Gasoline-engines … 24, 37, 65, 125, 131, 179, 210, 218–225, 232–234, 248, 259, 277

Gasoline-evaporator … 37, 65, 148

Gears … 114, 117, 136, 137, 168, 174, 175, 177, 237, 241

Gibson, Captain, recorder … 250

Goldbeater’s skin, for wings … 77

Goode, G. Brown … 97

Government allotment (‹see also› Board of Ordnance and Fortification) … 124–126, 132, 279

Gravity, center of … 10, 13–16, 45–52, 61, 64, 80, 91, 98, 101, 103, 143, 144, 150, 209, 210

Gravity-feed … 239

Guiding (‹see› equilibrium and control; sustaining surfaces; and rudder).

Gun-metal … 174

Gunpowder … 24, 25

Guy-posts … 184, 189, 199, 266, 267, 268, 270, 274, 275

Guying, early systems of … 81, 84–91

― wire … 81, 84–90, 99, 164–173, 189, 191, 196, 199, 264, 266

Gyroscopic control … 78, 211

H

Harting’s formula … 19

Head resistance … 142, 165–167

Heating apparatus (‹see› burners).

Herring, A. M., assistant … 104

Hewitt, Mr., at rescue of Mr. Manly … 273

Hodgkin’s fund, aid from … 257

Holmes, W. H. … 286, 289

Horizontal flight, velocity required to sustain … 1, 16–19, 43, 91

― rudder … 8

Horse-power, exerted by rubber … 9, 22

― Maxim’s formula … 15

― required to sustain flight … 1

― developed … 28, 37, 55, 58, 64–69, 117, 179, 223, 233, 249

Hot-water engine … 24, 25

House-boat and launching apparatus … 92–109, 110–122, 148, 149, 156, 163, 269

Huffaker, E. C. … 44, 46

Hull, construction of … 30, 32, 36, 53, 60, 69, 75, 112, 118–121

― forms of … 30, 31, 32, 38, 60, 69

― resistance … 49, 69

― steel tubes for … 39, 69, 75, 112, 118, 120

I

Ignition (‹see› electric batteries and circuits).

Indian rubber for power (‹see also› rubber) … 21, 40

Internal work of the wind … 6, 42

Inclination, angle of … 41, 43, 83, 99, 100

Insulation … 144, 241, 257

Iron, use of … 63, 64, 114–117, 234, 236, 240

J

Jacket, cork, aviator’s … 273

― water … 220, 234, 236, 241, 247, 252

“John Crow” (bird of Jamaica), study of … 285

K

Kite, model flown as … 133, 154, 155

L

Langley. S. P. … 3, 4, 9, 18, 76–79, 93, 95, 102–108, 112, 123–126, 128, 131, 133, 135, 153, 156, 161, 179, 183, 184, 188, 211, 212, 219, 223, 230, 231, 257, 266–268, 270, 271, 287, 280, 281

― statement of … 124, 280

― letter of instructions from (‹see› appendix).

― study of “John Crow” bird (‹see› appendix).

― aerodrome, War Department report on … 277, 278, 279

“Langley type” of aerodrome … 77, 164, 208, 244, 266, 276, 278–281

― ― ― rudder … 77, 86

Lateral stability … 45–52, 97

Launching, difficulties of … 10, 11, 12, 92, 94, 96, 99

― methods of … 13, 94–97, 110

― of large machine … 265–267, 271–272, 276, 282

Launching-apparatus … 92–122, 134, 149, 156–163, 183, 185, 231, 257, 261, 265–267, 270, 272, 276, 282

― overhead … 5, 92–122, 133–135, 139, 142, 143, 145, 151, 152, 154, 156–163

― underneath … 134, 135, 145–147, 151, 152, 154, 156–163, 183

― weakness of … 265, 276, 282

Launching-car … 158, 159, 183, 184, 255, 258, 262, 266–268, 271, 272, 274, 277

Launching speed (‹see also› velocity) … 135, 161, 162

Law of the cube … 129, 130

Lewis, Captain I. N. … 250

Lift of propellers (‹see also› pendulum tests) … 61, 62, 66, 69, 77, 94, 99, 102, 105, 107, 151, 189, 192

Lilienthal, Otto, on efficiency of curves … 44

Lineal velocity … 1, 43, 110, 166

Liquid air … 154

Longitudinal stability … 45–52

Lubrication … 113, 177, 234, 239, 240

M

McDonald, Mr. … 266, 271, 272

McKinley, President William … 123, 124

Macomb, Major M. M., report of … 276–278

Maltby, Mr., machinist … 93–95, 102, 106

Man-carrying machine … 123, 125, 129, 130, 151, 153, 156–187, 234–250, 255–282

Manly, C. M., assistant in charge of experiments … 123, 129, 218–224, 265, 266, 268, 272, 276, 278

― ― ― engine … 219–225

― ― ― formula … 51

― John M., description of flight, by … 260–261

Maxim’s formula for horse-power … 15

Mechanical flight … 2–4

― ― theory of … 1

― ― Dr. Bell on … 4

― ― Mr. Langley on … 3–4

Mica, use of … 63, 72, 115, 257

Models (‹see also› aerodrome model description and trials).

― experiments with … 1, 133–155

― ― ― small … 6–14, 17, 19

― flight of (‹see› trials).

― launching of (‹see also› launching apparatus) … 92–122, 133, 134

― rubber-driven … 5, 8–24, 76

― steam-driven (‹see also› Nos. 4, 5, 6) … 134, 135

― steam, motor, and other … 30–40

Motive power (‹see also› engines, electricity, and fuel) … 8, 11, 21–29, 118

― discussion of … 11

Motors, available (‹see also› engines) … 11, 21–29, 278

― carbonic acid gas … 11, 24, 26, 28, 29, 39, 53, 54

― compressed air … 11, 24, 25, 26, 68, 112, 113

― construction of early types of … 30–40

― electrical … 24, 26, 27, 212, 262, 263

― gas … 26, 28, 37, 131, 137

― gasoline … 24, 37, 65, 125, 131, 179, 210, 218, 219, 224, 277

― gunpowder … 24, 25

― hot-water … 24, 25, 68

― rubber … 5, 8–24, 76

― steam … 24, 25, 30–40

― weight of (‹see also› weight of engines) … 116, 126, 130, 209, 247, 250

Mount Whitney, observations on … 123

N

Nash, Dr. F. S. … 276

National Museum, models in … 282

Needle-valve … 56, 57, 113

Nitric acid, use of … 71

Nomenclature of parts of aerodrome … 14, 15

O

Oiling systems … 113, 177, 234, 239, 240

Open wind, experiments in … 42, 99, 257, 271, 272

Ordinance and Fortification (‹see› Board of).

Oxygen, necessity of … 72

P

Paper covering for rudder … 86, 103

Pénaud, Alphonse, toy aeroplane designed by … 7–9, 21, 22, 40

― tail or rudder … 8, 12, 13, 50, 51, 79, 82, 107, 122, 139–147, 151, 152, 153, 209, 211, 213, 214, 216, 253, 264, 270–272

“Pendulum” test for lift … 60, 61, 66, 94, 131, 135, 211, 212, 214, 232

Percaline for wing covering … 194, 195

Pinion (‹see› gears).

Piston (‹see› engines and cylinders).

Pitch of propellers … 63, 69, 76, 94, 181

Plane (‹see also› wings and surfaces).

― dropper … 150

― surface, angle of inclination of … 6, 8, 41–45, 61, 83, 97, 99, 100

― velocity required to sustain … 1, 43, 110, 166

Pocketing of wings … 84, 86, 100, 195, 203

Potomac River, location of tests on … 93

Power (‹see also› steam, fuel, and electricity).

― development of … 8, 39

― formula for … 62

― generating apparatus … 112, 125

― relation to area and weight … 43

Power-gauge (‹see› dynamometer).

Powell, Major G. H., recorder … 250, 267, 276

Press, attitude of … 127, 268

― report to, Mr. Langley’s … 280

― ― ― Mr. Manly’s … 266–267

Pressure, center of … 7, 10, 11, 13, 15, 45–52, 64, 78, 80, 84, 87, 88, 90, 91, 200, 209, 210

― ― ― rules for locating … 49, 87, 88, 90, 101

― ― ― and center of gravity … 10, 11, 15, 46, 48, 64, 98–101, 103

― steam … 24, 30–40, 53–59, 63–75, 101, 114, 117, 134, 135, 137, 141, 142, 149, 150

Pressure-gauge … 114

Prony-brake … 38, 61, 65, 66, 117, 179, 222, 228, 233, 249

Propellers … 7, 8, 11, 13, 22, 40, 68, 69, 94, 95, 102, 103, 108, 109, 118, 119, 136, 139, 143, 145, 149, 178–184, 258, 261, 262, 268, 272, 277

― construction of … 63, 76, 98, 100, 178–184

― early forms of … 7, 8, 11, 22, 33

― lift of … 61, 62, 66, 69, 77, 94, 102, 105, 107, 131, 148, 151, 189, 192

― pitch of … 63, 69, 76, 118, 181

― position of … 39, 63

― shafts of … 39, 117, 175–177, 242

― slip of … 107, 109

― speed of (‹see also› revolutions per minute) … 61, 91, 94, 99, 107, 114, 134, 264, 272

― tests of (‹see› pendulum, lift, and thrust).

― thrust of … 47, 62, 94, 119, 148, 154, 161, 174

― toy … 7, 8, 9, 21, 22

Pumps … 36, 37, 57, 59, 65, 68, 71, 75, 114, 115, 141, 241

― centrifugal … 241, 248

― circulating … 114, 244

― double-acting … 68, 114

― force … 57

Q

Quantico, Va., flights at … 64, 66, 79, 93, 147, 255, 269

Quarter-size model … 158, 159, 170, 226–233, 243, 255, 257–261, 281

Quill, eagle’s, and spruce rib compared … 200, 201

R

Radiator (‹see also› engine, water-cooled) … 252

Randolph, Gen. W. F. … 276, 277

Record of flights (‹see also› data sheets) … 2, 3, 17, 107, 117, 135–155, 255–282

Reed, R. L., chief carpenter … 93–95, 102, 106, 266, 271, 272, 275

Reel attached to float … 119, 120

Relation of area to weight and power … 43, 44, 64, 81, 89, 90, 99

Reservoir (‹see› air-chamber and tank).

Resistance, air … 6, 8, 9, 142

― of frame and guy-wires … 165–167

Revolutions of engine and propellers per minute (‹see also› speed) … 33, 58, 63, 65, 66, 102, 109, 115, 249, 252

Rib, spruce and eagle’s quill, compared … 200, 201

Ribs, construction of … 37, 80, 81, 86, 89, 188, 194–206, 263, 264

Ridgway, Robert, on American Buzzard … 301

Root-angle of wings … 82, 83, 91, 98, 100, 101, 103

Rotation, angle of … 61

― center of … 62

Rubber as a source of power … 5, 8–24, 44, 76

― elastic limit of … 9, 22

― “fatigue” of … 23

― horse-power produced by … 9, 22, 23

― springs … 2, 185

― insulation … 144, 241

Rubber-driven models … 5, 8–22

Rubber-pull and rubber-twisted models … 16–24

Rudder (‹see also› tail) … 8, 9, 77, 80–91, 122, 136, 207–217, 255, 272, 275

― horizontal … 8

― Pénaud’s … 8, 12, 13, 50, 79, 87, 107, 122, 139–147, 151, 209, 211, 213, 214, 216, 253, 270–272, 275

― vertical evolution of … 81, 82, 86, 97, 101, 106

Rudder-tail (‹see› tail-rudder).

S

Sanding-tests of wings … 84, 85, 89, 99, 190–204

“Separator,” evolution of, for dry steam … 58, 59, 65, 68, 114, 142

Serpollet-type boilers … 56, 57

Shafts, main, construction of … 117

― propeller … 39, 117, 175–177, 242

Sharp, Archibald, on balancing of engines … 246

Sheathing, aluminum … 69

― mica … 63, 72, 115

Shop tests … 40, 218, 251–254

Silk wing-covering … 54, 63, 81, 86–88, 90, 148, 194, 195, 205

Sliding tail designed … 16, 84

Smillie, Thomas W., photographer … 260, 267, 271, 273

Smithsonian Institution … 1, 6, 17, 18, 31, 42, 124–126, 171, 174, 176, 179, 257, 260, 271, 276, 280–281

Smoke-stack … 60, 67, 74, 78

Soaring birds, study of (‹see also› appendix) … 7, 9, 88

Soaring-speed … 32, 41, 69

Sparking devices (‹see› electric batteries and circuits).

Specific gravity … 120

Speed attained (‹see also› velocity) … 31, 32, 41, 55, 61, 91, 99, 107, 114, 134, 161, 264

Speed-counter … 62, 120, 185, 243, 249, 252

Spokes, wire … 243

Spruce guy-sticks and frames … 85–87, 90

― ribs compared with quills … 200, 201

St. Louis Exposition tests … 249

Stability, lateral and longitudinal … 45–52, 77

Starter on launching-car … 94, 95

Starting-crank on launching-car … 243, 244

Steam, dry, production of … 58

Steam-chest … 117

Steam-engine … 24, 30–40, 64, 69, 116, 120

Steam-gauge … 114

― construction of frames and … 53–80

Steam-generating apparatus … 114–116

Steam-motors and other models … 30–40, 134, 135

Steam-pressure … 24, 30–40, 53–59, 63–70, 101, 102, 114, 117, 134, 135, 137, 141, 142, 149, 150

Steel, use of … 69, 112, 116, 119, 121, 172, 174, 234, 277

― tubes, for hull … 39, 69, 75, 112, 118, 120

Steering apparatus (‹see also› equilibrium and control) … 214–216, 265, 266, 272

― ― automatic … 30, 77, 211, 216

Steering wheel … 214, 216, 265, 266, 272

Storage batteries (‹see› batteries, electrical).

Stringfellow engine … 30, 31

Superposed wings … 13, 14, 17, 138, 153, 193, 231

Supporting surfaces … 11, 44, 77, 81, 99, 188–206

Supports for propellers … 112

― ― wings and tails … 36, 69

Surfaces (‹see also› planes and wings).

― covering for … 77, 81, 86, 87, 90, 148, 194, 195

― curved … 44, 46

― plane, observations on velocity of … 1

― rigid … 6, 46

― supporting … 11 44, 77, 93, 99 188–206

― sustaining … 1, 5, 41–44, 80–91, 99

― ― and guiding … 5, 80–91

Surgeons’ tape, used for mending ribs … 264

Sustaining surface … 1, 5, 41–44, 80–91, 99

― ― de Lucy on … 19

Symbols … 14, 15

Synchronizing mechanism … 108, 121, 136, 137

T

Table, turn … 156, 165, 166

― whirling … 1, 5, 6, 7, 11, 13, 31, 42, 165, 166, 178, 189–194

Tachometer … 62, 120, 185, 243, 249, 252

Tail … 8, 9, 70, 77, 80, 91, 99, 207–217

― adjustment of … 16, 84

― connections of … 84, 213–216

― covering … 86 103

― Pénaud … 12, 13, 50, 79, 107, 122, 139–147, 151–153, 209, 211, 213, 214, 215

― sliding … 16, 84

― use as guiding and sustaining surface … 80

Tail-rudder … 77, 86, 87, 119, 152, 153

― Langley … 77, 86

Tank, air … 64, 68, 69, 112, 114

― fuel … 36, 65–68, 112, 113

― water … 252

Telephoto camera … 260, 261, 273

Tests (‹see also› engine tests, trials, and flights).

― boilers … 70–75, 135

― construction and … 234–250

― cylinder … 55

― engine … 37, 55, 61, 69, 102, 133, 135, 148, 234–250, 251–254, 281

― experimental engine … 1902–1904 … 250

― frame … 79

― power … 61, 62, 69, 102

― resistance … 165–167

― sanding, of wings … 84, 85, 89, 90, 190–204

― shop, of large machine … 40, 218, 251–254

― St. Louis Exposition … 249

― whirling-table … 1, 5, 6, 7, 11, 13, 31, 42, 165–166, 178, 189–194

― wing … 84, 85, 89, 99, 190–204

Testing ground (‹see also› Quantico) … 64, 66, 92, 93, 255, 256, 277, 280

Thrust, center of … 62

― propeller … 47, 62, 94, 119, 148, 154, 161, 174

Thrust-recording devices … 229, 230

Thurston, R. H. … 128, 129

Time of flights … 103, 107, 108, 109, 137, 145, 148, 258

Torque … 222, 242

Toy aeroplanes … 7, 9, 21, 22, 40

Transmission (‹see also› shaft and gears) … 117, 175–177, 242

Transverse frame … 77, 165, 174–178

Trials, first … 97

― (1891) … 17

― (1892) … 53, 92

― (1893) … 65, 93–96

― (1894) … 65, 96–100

― (1895) … 101–106

― (1896) … 2, 79, 106–109

― (1897) … 123–125

― (1898) … 61

― (1899) … 79, 135–155

― (1903) … 126, 181, 255–282

Tubes in hull construction … 69, 112, 116, 119, 120, 172, 174, 234, 277

Turn-table … 156, 165, 166

Turnbuckle (‹see also› guying) … 170, 171, 172

V

Valve-chest … 114, 213

Valves … 114, 117, 213

― exhaust … 237

― mechanically operated … 114, 213

― motion … 112, 114, 115, 213

― needle … 56, 57, 113, 212

Vaporization … 37, 67, 148, 149

Varnish, collodion … 192

― not affected by ammonia … 198

― pyroxelene … 86

― water-proof … 263, 264

Velocity … 18, 31, 32, 55, 91, 99, 107, 109, 114, 134, 150, 161, 166, 185, 264, 265

― initial … 100, 110, 150, 163

― required to sustain plane … 1, 43, 110, 166

Vertical rudder … 81, 82, 86, 97, 101, 106

Vulcanite, use of … 257

W

War Department, allotment … 124–126, 132, 278, 279

― ― Board of Ordnance and Fortification … 124–126

― ― ― ― ― ― ― Report of … 276–280

Washington Evening Star, report of … 274

Watches, stop, for timing flight … 109

Water, cooling, for engine … 235, 236, 241, 247, 248, 252

Water-engine, hot … 24, 25

Water-jacket … 220, 234, 236

Water-proof varnish … 263, 264

Water-tank … 252

Watkins J. E. … 39

Weight (‹see also› data sheets).

― flying, of aerodrome … 15, 38, 62, 63, 76, 77, 81, 89, 90, 91, 101, 109, 116, 148, 206, 247, 250, 256, 277

― of aerodrome … 31, 38, 40, 53, 62, 63, 116, 126, 130, 206, 256

― ― covering for wings … 194

― ― parts of aerodrome … 31, 63, 116, 190, 250

― ― engine … 116, 117, 126, 130, 156, 209, 247, 250, 277

― per horse-power … 31, 126

― relation to area and power … 43, 44, 64, 81, 89, 90, 96

― total, with aviator … 256

Wellner, Georg … 44, 47

Wheel, fly … 242, 243, 247, 252

― steering … 214–216, 265, 266, 272

Whirling-table … 1, 5, 6, 7, 11, 13, 31, 42, 165–166, 178, 189–194

Widewater, Va., experimental grounds (1903) … 255, 256, 277, 280

Wind, artificial … 42, 61

― difficulties of launching in … 94, 99, 265, 271, 272, 276, 282

― experiments in … 42, 61, 99, 257, 271

― internal work of the … 6, 42

― open … 42, 99, 257, 271, 272

Wind-shield for burners … 60, 67, 95, 115

Wind-vane rudder … 136

Wing-clamps … 82, 89, 145, 183

Wings, adjustment of, for center of gravity … 16

― angle of … 45, 61, 82, 83, 89, 91, 97, 98, 100, 101, 103

― arrangement of … 45–47, 77, 86, 89, 194, 255

― bagging of … 84, 86, 100, 195, 203

― bird, construction of … 7, 188, 200, 201

― boxes for … 263, 264

― construction of … 7, 70, 80, 81, 87, 90, 91, 99, 105, 119, 121, 138, 188–206

― covering of, cloth … 195, 199, 204, 205

― ― ― goldbeater’s skin … 77

― ― ― paper … 86

― ― ― silk … 54, 63, 81, 86–88, 90, 148, 194, 195, 205

― ― ― weight of … 194

― curvature of … 18, 44, 46, 47, 86, 87, 90, 99, 112

― distortion of … 82, 83, 84, 91, 98, 105

― double tier … 13, 14, 17, 138, 193, 231

― efficiency of … 46, 87, 89, 91, 144, 192, 193

― flexure of (‹see› distortion of).

― pocketing of … 84, 86, 100, 195 203

― quills and spruce ribs compared … 200, 201

― ribs of … 37, 80, 81, 86, 89, 188, 194–206

― single tier … 17, 142, 146, 147–151, 153, 192, 193, 231

― superposed … 13, 14, 17, 138, 153, 193, 231

― surface of … 9, 69, 81, 99

― tandem efficiency of … 46, 87

― two sets of … 13, 77, 106, 138, 231

― weight of … 190, 196

Wire guying … 81, 84–91, 99, 164–173, 189, 191, 195, 196, 199, 264, 266

― resistance … 165–167

― spokes … 243

Wooden guy sticks … 63, 81, 85

― ribs … 37, 80, 81, 86, 89, 188, 194–206, 263, 264

Wrecking of large machine … 126, 184, 265–281

Z

Zinc, energy developed from … 27, 241

Zoological Park cameras … 260, 261, 273

TRANSCRIBER'S ENDNOTE

Original spelling and grammar have been generally retained, with some exceptions noted below.

Illustrations are moved from inside paragraphs to between paragraphs.

Footnotes have been renumbered and moved from the ends of pages to the to the ends of the appropriate sections, which are: Advertisement (page iii); Part I; and Part II, up to just ahead of the DATA SHEETS, which have their own footnotes, which were neither moved nor renumbered.

Pages 16–18. Page 16 ended at "with another one, No. 31, also shown", followed by Plates 1–4, followed by page 17, which contained two data tables, followed by page 18, which continued the original paragraph. The transcriber has closed the paragraph, and moved the Plates and tables to follow it.

Pages 31–32. The footnote on page 31 said only "See footnote on page 32." The footnote on page 32 had no anchor in the text. Therefore, to simplify, the page 31 footnote has been eliminated, and its anchor is linked directly to the page 32 footnote. Pages 46–47. The footnote on page 47 had no anchor in the text. However, the footnote on page 46 said only "See Footnote page 47". Therefore, the footnote anchor on page 46 has been linked directly to the footnote on page 47, eliminating the page 46 footnote.

Page 63. The large table was split into two tables, repeating the first column in each part. Large curly brackets "}", "{", indicating combination of information on two or more lines, have been replaced by Unicode box drawing characters, e.g. "│┌┘└┐". Tables in general, and these box characters in particular, may not line up properly unless the user is employing a monospaced font.

Page 140. The paragraph for June 23 originally ended "dotted line in Plate". The transcriber has inserted " 34.", as a guess.

Pages 190–192. The wide tables were split into two, repeating the first column in each part.

Page 193. The wide tables were transposed, row for column.

Page 201. The wide table was split into two.

Pages 297–308, Data Sheets. Remarks originally situated in the tables are appended below each Data Sheet. The units of measurement were originally spelled out—‹m.›=‹Metres›; ‹ft.›=‹Feet›; ‹gr.›=‹Grammes›; and ‹lbs.›=‹Pounds›. In the footnotes to the Data Sheets, in the phrases "curved wings 2-5 the way", and "rear wings have 2-3 of the efficiency", the hyphen seems to mean division, like "/". This usage occurs also in the caption to Plate 85, in "SCALE 1 1-16 INCH TO STATUTE MILE".

Page 299. Item 41, "7 75" changed to "7.75".

INDEX. The original index was structured in a way not suitable for this ebook. The white space on the printed page substituted for words not repeated. Thus, under "Balancing of aerodrome, [ ... ]", were indented entries for "engine", "wings and rudder", &c. This spacing has been rendered herein as a horizontal bar "―", one for each word to be understood as repeated. So in this case, two bars, meaning "Balancing of". Moreover, page numbers referenced by index entries were right-justified and preceded by dotted leaders. Herein, the leaders have been indicated by horizontal ellipsis "…". The leaders in the Table of Contents have also been replaced by ellipses.

Estimating from Internet Archive's stated scanning rate of 400 ppi, the pages were about 6.2 by 9.2 inches. Body text was printed in 9 point type, with 3 point leading, and footnotes were printed in 5.4 point type.