Chapter 3

The discussion was continued with considerable vigor by Messrs. H. Fisher (vice-president), James Rigby, J. Tibbs, M. Millard, Walker, W. Yeomans (secretary), and others. Several of these gave it as their experience that the best castings contained the most blowholes, and Mr. McCallem accepted the pronouncement, with some slight qualification.

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SCIENCE IN DIMINISHING CASUALTIES AT SEA.

At the recent meeting of the British Association, Don Arturo de Marcoartu read a paper on the above subject.

He stated that he wished to draw special attention to increasing the safety of navigation against storms, fogs, fire, and collisions with wrecks, icebergs, or vessels, and recommending the development of maritime telegraphy. He urged that vessels should be supplied with apparatus to communicate with and telegraph to each other and to the nearest coast the weather and sea passed over by them, and that reports given by vessels should be used as "warnings" more extensively. He wished the mid-Atlantic stations connected by telegraph for the same purpose.

In regard to the use of oil on rough seas, he said that Dr. Badeley in 1857, Mr. John Shields five years ago at Peterhead and last year at Folkestone, the Board of Trade in 1883, and a committee on life saving appliances of the United States had made experiments. The conclusions of the committee were that in deep water oil had a calming effect upon a rough sea, but there was nothing in either source of information which yet answered the question whether or not there is in the force exerted by the wind a point beyond which oil cannot counteract its influence in causing the sea to break. He thought it appeared that oil had some utility on tidal bars; on wrecks, to facilitate the operations of rescue; on lifeboats and on lifebuoys. In regard to icebergs, he thought the possibility of obtaining an echo from an iceberg when in dangerous proximity to a ship should be tried. He advocated the use of automatic sprinklers in the case of fire, the establishment of parabolic reflectors for concentration of sound, and the further prosecution of experiments by Professor Bell in establishing communication between vessels some distance apart by means of interrupted electrical currents. The improvement of navigation, he said, meant an international code of police to improve police rules of navigation; an international code of universal telegraphy for navigation; an international office of meteorology and navigation to collect the studies; experiments on the weather, on the sea, on the casualties; and the discovery by experiment of new apparatus and appliances to diminish maritime disaster.

He had called the attention of two governments to this matter, and he hoped that before long there would be proposed an international congress--such as the postal, telegraph, and sanitary congresses, and the international convention to fix the common meridian--by one of the maritime powers, by which would be founded an international institution to diminish casualties at sea. He recommended a universal system of buoys. The great losses of life and property every year were worthy the devotion of £300,000 by an international institution, which would be much less than the monthly average loss in navigation.

Admiral Pim said that ships were improperly built--some were ten times longer than their beam. There was nothing in the world so ticklish as a ship; touch her in the waist, and down she goes. He believed sailing ships ought not to exceed four times their beam, and steamers certainly not more than six times. He pointed out that a fruitful cause of accidents was the stopping of steaming all at once in the case of impending collision, by which the rudder lost control of the vessel. If constructors looked more to the form of the ships, and got them to steer better, collisions would be avoided.

The Lord Advocate said it had always occurred to him that one great secret of collisions at sea was the present system of lights, which made it impossible for the vessel at once to inform another vessel what it was about. The method of signaling was very crude, and he ventured to say that it was quite out of date when vessels met each other at a rate of speed of 24 to 25 knots. He had, as an amateur, tried a method which he would attempt to explain. His idea was to fit up a lantern on deck, showing an electric light. The instrument would be controlled by the rudder, and the commanding officer of the vessel would be able so to turn it when the helm was put up or down that the light would flash at some distance in front of either bow of the vessel, and thus be a signal to a vessel coming in an opposite direction. When the helm was amidships, the light was shown straight ahead, and could not be moved until the helm was shifted. The direction in which the vessel was going could not by any possibility be mistaken, and it was plain that if the lights from two ships crossed each other, then there was danger. If the lights were clear of each other, then the ships would pass safely.

Sir James Douglass asked if his Lordship had made any experiments.

The Lord Advocate said he had not. The Board of Trade had such a number of inventions on this subject on hand that he supposed they were already disgusted. Besides, he was only an amateur, and left the carrying out of the suggestion to others.

Sir James Douglass said this idea of a lantern did very well for a short distance, but for a long distance it utterly failed. It was very difficult to realize a movement from a distance of over a mile out to sea, and signals were required to be visible for from two to three miles.

The Lord Advocate said his idea depended not upon the object light, but upon the sweep of the light on the water.

Sir James Douglass said all those questions were of the utmost importance to a maritime country. In regard to experiments with oil on troubled water, he had witnessed them, and he had carefully studied all the reports, and had come to the conclusion that they were all very well in a tub of water or a pond, but on the ocean they were utterly hopeless. He would stake his reputation on that. They had been tried in the neighborhood of Aberdeen, and he had prophesied the results before they were commenced. It was utterly hopeless to think that a quantity of oil had the power of laying a storm--all the world could not produce oil enough to bring about that result.

There might be something in maritime telegraphy, and he hoped the experiments of Mr. Graham Bell, in transmitting through two or three mile distances, would come to something. He did not believe in powerful lights. Increase the lights to any very great extent, and a dazzling effect was the result. In regard to sound, he wondered that no more effective alarm was used than the whistle. It was well known that, as the whistle instrument was enlarged, the sound became more and more a roar. He would have ships use all their boiler power in sounding a siren, so that the sound could be heard at a distance of not less than two or three miles in any weather. With such a signal as that there ought to be, not absolute safety, but collisions would be more easily prevented. He was glad to say that a universal system of buoys had been practically arranged, thanks to the Duke of Edinburgh and his committee, so that, as soon as an old system can be changed to a new one, all the buoys would bear one universal language.

Admiral Pim pointed out that a red light would show four miles, while a green light was only visible for two miles and a half, so that, if a green light were seen, it indicated that the two vessels were within two miles and a half of each other.

Sir James Douglass said there was undoubtedly a weakness in regard to these lights; and he held that in the manufacture of lights effect should be given to the difference that existed in the various lights, so that, by making the green light more powerful, it could penetrate as far as the red, and in the same way making the red and green lights proportionately more powerful, so that they would penetrate as far as the white light.

Sir James Douglass said he had seen a parabolic reflector for sound tried, but, unfortunately, the reflector so intensified and focused all the sounds about the vessel and the noise of the sea that the operator could hear nothing but a chaos of sound.

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A PLAN FOR A CARBONIZING HOUSE.

The operation of carbonizing woolen rags for the purpose of obtaining pure wool, through the destruction of the vegetable substances contained in the raw material, maybe divided into two parts, viz., the immersion of the rags in acid, with subsequent washing and drying, and the carbonization properly so called. The first part is so well known, and is so simple in its details and apparatus, that it is useless to dwell upon it in this place. But the second requires more scientific arrangements than those that seem to be generally adopted, and, as carbonization is now tending to constitute a special industry, we think it is of interest to give here a typical plan for a plant of this kind. It will be remarked that this plan contains all the parts in duplicate. The object of this arrangement is to permit of a greater production, by rendering the operation continuous through half of the apparatus being in operation while the other half is being emptied and filled.

Figs. 4 and 5 give plans of the ground floor and first story, and Figs. 1, 2, and 3 give vertical sections. The second story is arranged like the first, and serves as a drier. As we have said, there is a double series of chambers for carbonization, drying, and work generally. These two series are arranged on each side of a central portion, which contains the heating and ventilating apparatus and a stone stairway giving access to the upper stories. The heating apparatus is a hot air stove provided with a system of piping. The rags to be carbonized or the wool to be dried are placed upon wire cloth frames.

The carbonization is effected in the following way: When the heating apparatus has been fired up, and has been operating for about half an hour, the apertures, i, are opened so as to let the air in, as are also those, m, which allow the hot air to pass into the chambers. The hot air then descends from the top of the chamber into the wool or rags, and, becoming saturated and heavier, descends and makes its exit from the chamber through an aperture, n, near the floor, whence it flows to the central chimney. This latter, which is built of brick or stone, contains in its center a second chimney (formed of cast or forged iron pipes) that serves to carry off into the atmosphere the products of combustion from the heating apparatus. The heat that radiates from these pipes serves at the same time to heat the annular space through which the vapors derived from the wool are disengaged.

The air, heated to 40° or 50°, is made to pass thus for several hours, until the greater part of the humidity has been removed. The temperature is then raised to 80° or 90° by gradually closing the apertures that give access to the ventilating chimney. In order that it may be possible to further increase the temperature during the last hour, and raise it to 90° or 120°, an arrangement is provided that prevents all entrance of the external air into the heating apparatus, and that replaces such air with the hot air of the chamber; so that this hot air circulates in the pipes of the stove and thus becomes gradually hotter and hotter. The hot vapors that issue from the lower chamber rise into the upper one, where they are used for the preliminary drying of another part of the materials.

The hot air stove should be well lined with refractory clay, in order to prevent the iron from getting red hot, and the grate should be of relatively wide surface. All the pipes should be of cast iron, and all the joints be well turned. Every neglect to see to such matters, with a view to saving money, will surely lead in the long run to bad results.

The mode of work indicated here is called the moist process. It necessitates the use of a solution of sulphuric acid, but, as this latter destroys most colors, it cannot be used when it is desired to preserve the tint of the woolen under treatment. In this case recourse is had to the dry process, which consists in substituting the vapors of nitric acid heated to 115° or 125° for the sulphuric acid. The arrangement of the rooms must likewise be different. The chambers, which may be in duplicate, as in the preceding case, are vaulted, and are about three yards long by three wide and three high. The rags are put into wire cages that have six divisions, and that are located in the middle of the chamber, where they are slowly revolved by means of gearings. Under the floor are the heating flues, and upon it is a reservoir for holding the vessel that contains the acid to be vaporized. The arrangements for the admission of air and carrying along the vapors are the same as in the other case. Great precaution should be taken to have the flues so constructed as to prevent fire.--_Bull, de la Musee de l'Industrie_.

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APPARATUS FOR EVAPORATING ORGANIC LIQUIDS.

According to Mr. D'A. Bernard, it is especially important, in the dry distillation of distiller's wash in a closed vessel, for the production of methyls, ammonia, acetates, and methylamine, that the mass shall be divided as completely as possible, since it then takes but a relatively moderate heat to completely destroy the organic coloring matter contained in the wash. The apparatus shown in Figs. 1 and 2 is based upon this observation.

The wash enters, through the hopper, D, and the valve, z, a long boiler, B, which is heated by the furnace, F, through the intermedium of a waterbath, w. An agitator, E, moves the mass slowly to the other extremity of the boiler, from whence it makes its exit in the form of dust. To the frame, E, are fixed the scrapers, b, and the interrupted pieces, a, in front of which are the hinged valves, c. In the motion of the pieces, a, from right to left, these valves free the apertures thereof and allow the wash to pass, while in the motion from left to right the apertures are closed and the valves push the mass to be evaporated before them.

From any motor whatever, the frame, E, receives a double to and fro motion in a horizontal and vertical direction, the latter of which is produced by the rods, f, which are provided at their lower, forked extremity with rollers, e, over which passes the piece, d, that supports the frame, E. At their upper part the rods, f, pass through the side of the boiler, through the intermedium of stuffing boxes, and are connected by their upper extremities, through a link, with levers, g, that revolve around the point, h. A cam shaft, M, communicates a temporary, alternately rising and descending motion to the levers, g, and the rods f. The same shaft, M, opens and closes the valve, z, of the hopper, D, and thus regulates the entrance of the wash into the boiler. The frame, E, receives its horizontal to and fro motion from the rod, l, which traverses a stuffing-box and is moved by a crank on an eccentric, m. The material in powder derived from the evaporation of the wash is stored at the extremity of the apparatus into a lixiviating vessel, G, provided with a stirrer, H. The salts and other analogous matters are dissolved, and the residuum, which constitutes a carbonaceous mass, is forced out of the apparatus, while the solution passes directly to the refinery, where it is evaporated.

In manufactories where no refining is done, the crude potassa in powder is pushed on to a prolongation of the apparatus which is cooled by means of water, and is removed from time to time with shovels by the workmen, so that the orifice of the boiler remains constantly covered externally by the mass, and that the air cannot re-enter the apparatus.

The gases disengaged during the operation pass into a cooler, where they condense into a liquid which contains ammonia and methylamine. The non-condensable part of the gases is burned in the furnace of the manufactory.

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IMPROVED LEVELING MACHINE.

In the American Court of the Inventions Exhibition, London, we find a leveling machine for sheet metals exhibited by Mr. J.W. Britton, of Cleveland, Ohio, and which we illustrate.

This apparatus is intended to supersede the cold rolling of plates in order to take the buckle out of them. The sheets are clamped in the jaws or grips shown, and the stretch is effected by means of a hydraulic ram connected directly to the nearest pair of jaws. The power is obtained by means of a pair of pumps run through spur-gearing by the belt pulleys shown. The action of the machine puts a strain on those parts of the plates which are not "bagged" or buckled, and this causes the surface to extend, the slack parts of the plate not being subject to the same stretching action. The machine shown is designed to operate on sheet iron from No. 7 to No. 30 gauge, and up to 36 in. wide, the limit for length being 120 in. About a dozen sheets can be operated on at once. The machine appears to have met with considerable success in America, and has been used for mild steel, iron, galvanized or tinned sheets, copper, brass, and zinc. The details of this machine are given in Figs. 1 to 8. Figs. 1 and 2 are a plan and side elevation of the bed of the machine, showing the position of the hydraulic ram. Fig. 3 shows the bars used for holding the back jaws in position, with the holes for adjusting to different lengths of the plates. Fig. 4 is a back view and section of the crosshead and one of the bolts that connect the moving grip with the hydraulic ram. Fig. 5 gives a plan and cross section of the back grip, and Fig. 6 is a back elevation of the same, with a front view and section of the gripping part. Fig. 7 shows the gear by which the jaws are opened and closed.

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THE SCHOLAR'S COMPASSES.

Among the numerous arrangements that have been devised for drawing circles in diagrams, sketches, etc., one of the simplest is doubtless that which is represented in the accompanying figure, and which is known in England as the "scholar's compasses." It consists of a socket into which slides a pencil by hard friction, and to which is hinged a tapering, pointed leg. This latter and the pencil are held at the proper distance apart by means of a slotted strip of metal and a binding screw. When the instrument is closed, as shown in the figure to the left, it takes up but little space, and may be easily carried in the pocket without the point tearing the clothing, as the binding screw holds the leg firmly against the pencil.

The mode of using the apparatus is so well shown in the figure to the right that it is unnecessary to enter into any explanation.--_La Nature_.

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THE INTEGRAPH.

In scientific researches in the domain of physics we often meet with the following problem: Being given any function whatever, y = f(x), to find a curve whose equation shall be

_ / | y = | f(x)dx + C. | _/

[TEX: y = \int f(x) dx + C.]

Let us take an example that touches us more closely; let us suppose that we know an induced current, and that we can represent it by a curve y=f(x). The question is to find the inductive current, that is to say, the curve represented by the equation

_ / | y = | f(x)dx + C. | _/

[TEX: y = \int f(x) dx + C.]

The apparatus called an integraph, constructed by Messrs. Napoli and Abdank-Abakanowicz, is designed for solving this problem mechanically, by tracing the curve sought. Let us take another example from the domain of electricity, in order to better show the utility of the apparatus; let us suppose that we have a curve representing the discharge of a pile or of an accumulator. The abscisses represent the times, and the ordinates the amperes. The question is to know at every moment the quantity of coulombs produced by the pile. The apparatus traces a curve whose ordinates give the number of coulombs sought. We might find a large number of analogous applications.

The apparatus is represented in the accompanying figure. An iron ruler, I, parallel with the axis of the X's, is fixed upon a drawing-board, and is provided with a longitudinal groove in its upper surface. In this groove move two rollers, which, in the center of the piece that connects them, carry two brass T-squares that are parallel with each other and at right angles with the first, or parallel with the axis of the Y's. Between these two rulers move two carriages, the first of which (nearest the axis of the X's) carries a point, A, designed to follow the contour of the curve to be integrated, while the second, which is placed further away, is provided at the center with a drawing-pen, A', whose point is guided by two equidistant wheels, R, R', that roll over the paper in such a way as to have their plane parallel with a given straight line, and that have always a direction such that the tangent of the point's angle with the axes of the X's is constantly proportional to the ordinate of the primitive curve.

The carriages are rendered very movable by substituting rolling for a sliding friction of the axes. To this effect, the extremities of the axes of the wheels that support and guide them are made thin, and roll over the plane surface of recesses formed for the purpose in the lateral steel surfaces of the carriages, while the circumference of the wheels rolls in grooves along the two T-squares.

These latter are, on the one hand, carried by rollers that run in the groove of the iron, I, and, on the other, by a single roller that runs over the paper. At right angles with one of these bars is fixed a divided ruler, through one point of which continually passes a third ruler, whose extremity pivots upon the point, A, of the first carriage.

When the divided ruler is placed upon the axis of the X's, and the point, A, of this carriage is following the contours of the figure to be integrated, the tangent of the angle made by the inclined ruler with the axis of the X's will be proportional to the ordinate of the figure. The wheels, R and R', of the drawing-pen, A', of the second carriage must move parallel with this ruler. In order to obtain such parallelism, we employ a parallelogram formed as follows: Two gear-wheels of the same diameter are fixed upon the ruler that ends at the point, A, of the first carriage, and their line of centers is parallel with the latter. The second carriage likewise carries two drums equal in diameter to those of the toothed wheels. These are fixed, and their line of centers must remain constantly parallel with the line of centers of the gear-wheels, and consequently with the straight line which passes through the point, A. This parallelism is obtained by means of a weak steel spring, or of a silken thread passing over the four wheels, the two first of which (the gear-wheels) hold it taut by means of a barrel and spring placed in the center of one of them.

The edge of the wheels, R, R', of the second carriage prevents the latter from giving way to the traction of the threads, permitting it thus to move only in the direction of their plane.