Part 8
I suggest that the propelling wheels be placed in some other position than that given in the said description. From what little knowledge I possess of aerial navigation, I am persuaded that it would take less power to propel the "Aeroport" at a given speed, if the wheels were placed at the rear or front portion of the flying ship. My reason for being thus persuaded is, that as the forward and aft halves of the float are cone-shaped--the center being the base, and the front and rear ends being the vertexes--there must be an increased velocity of the atmosphere from front to aft as the aeroport advances. Consequently the driving wheels being placed under the center or largest diameter of the float, they must evidently revolve with greater rapidity in the current of air passing between the float and the saloon, going in opposite direction to that in which the aeroport is flying at a given speed, than they would were they placed in front or behind where the atmosphere is comparatively at rest. I take this view from the fact that steamboats and other vessels proceed with greater speed, with a given power, _down_ stream than they do _up_ stream, mostly on account of the paddles striking against the current flowing in the same direction in which the vessel is rowing. The propelling wheels placed either at the front or rear may have the axle extended through the end of the float to the center, and the cog-wheel, for the chain, placed on the inner end of the axle, and the chain descending through the bottom of the float, and connected to the engine in the same manner as given in your paper. The chain should be inclosed from the float to the saloon below, with a pipe of the same material as the float, and sufficiently large to insure the free action of the chain, and the axle of the propellers should be made tight with suitable packing to prevent the escape of gas. However there may be different arrangements employed for connecting the engine to the wheels. A shaft extending directly under the float, and reaching from the center to the axle supporting the propellers, and connected therewith by means of side cog-wheels, might be used; and as the shaft would necessarily diverge from a straight line with the said axle, the shaft having the chain-wheel on the end directly over the engine and connected therewith in the manner proposed by Mr. Porter, I would suggest further that it would, perhaps, be preferable to place the wheels at the front end, that the rudder might remain in its original position, and the aeroport could swing behind the propellers on encountering side currents of air, and could thus be more easily guided. I firmly believe that Mr. Porter has taken "the right step in the right direction" to accomplish that which has been so long sought, and which evidently will be accomplished at some future time. The air will yet be navigated by numerous flying ships, going from one city to another like those that now cover the broad bosom of our oceans.
HIRAM VAN METER.
Macomb, Ill.
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Puttying Floors of Jewelers Shops and Otherwise.
Messrs. Editors:--I am a reader of your valuable paper and find in it much to interest, and many practical hints that are useful in my vocation; I would not be without it for any consideration and I think every mechanic in the land should take it, read it, and profit by the reading.
I notice, in Vol. XXI, page 371, a communication headed, "Watch Repairers' Shop," in which directions are given to fill the chinks in the floor around the work-bench with soft pine and putty, etc., etc.; this is all well enough, but will not prevent the breaking of pivots should a balance wheel be dropped, neither will it prevent the wheel being stepped upon and so rendered useless, as often happens.
I am a watch-maker and jeweler, and I never drop a wheel or part of a watch on the floor. I have an apron about one yard wide, and in the corners of it are eyelet-holes, so that I can pin it to the bench when I am working; I have strings to it, but do not generally tie them around me, but let it be loose in my lap as I have to jump up, to attend to customers in the shop. In the shop where I learned my trade (in London, England), every workman was _compelled_ to wear an apron, and so much waste of property and valuable time was saved; the saving of _time_ in _one week_ will more than pay the cost of the aprons.
Sidney Plains, N. Y,
GEO. C.L. KENT.
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Western Demand for Agricultural Implements.
Messrs. Editors:--I often think, on perusing your very valuable journal of science, and the numerous mechanical and scientific problems it unfolds, that the tendency of the age is to supersede all manual labor by machinery. Whether such a thing is possible is not the question for me to consider; I only know that the tendency of universal human genius seems directed to that end.
I make the above observation casually, in order to introduce a few ideas on the subject of improvement in agricultural implements--the great _desideratum_ of the West at this moment. Here nature has opened her stores so munificently, that all the husbandman has to do is to plow, sow, and garner the fruits of his labor. But two great improvements are needed to enable the western farmer to keep pace with improvements in the mechanic arts and other kindred employment. Indeed, we at the West, particularly, need a good, cheap, steam plow that can be made practicable for at least the better grade of farmers. The English plan of moldboards, that overcome all possible traction and necessitate the duplex stationary engines, with the cumbrous "artillery of attachments," may do for sluggish people but will never meet the wants of the Yankee nation.
The steam plow suited to the genius of our people, must, to use a vulgarism, "get up and go." It must possess sufficient power of propulsion and traction to pulverize the ground better, deeper, and more rapidly than the "old way." Such is the want of the great West in reference to preparing the soil for crops. I do not know of such a machine in use, nor do I believe in the theory of Dr. Brainard, that the moldboard is the only plan for properly pulverizing the soil; for I am satisfied that such plan is wholly inadmissible in steam plowing in this country, for want of sufficient traction for self-propulsion, and observation has taught me that a self-propelling plow is the only steam plow our people will tolerate.
I have lately examined the drawings of a steam plow invented by a gentleman of this city (which I am not at liberty to explain in detail) that seems to meet the great want I have spoken of. The invention consists in a very simple device, by which the whole force of pulverizing the ground is applied to propel the machine, and if this be not sufficient, an independent force may be applied, so arranged as to govern the speed of the machine at the will of the operator. You will, no doubt, in due time hear more of this machine, which seems to me to meet the great want so long experienced in Western cultivation.
The next great want of the West is a practical grain binder, that shall securely bind the grain as cut. The scarcity and high price of labor renders such a machine an absolute necessity. The efforts to supply this great want have been numerous, but with no flattering success so far as I am able to learn, except the machine invented by a citizen of this place, which has already made its mark by demonstrating that automatic machinery can and does bind the grain as fast as cut. The machine I speak of is yet in a chrysalis state, so to speak, but it has been worked two years in the field, the last season without missing a bundle, though not without the usual difficulties of all new machines in respect to the workings of some parts--too weak, etc. It is believed that the coming harvest will witness its triumphant success. If so, the production of our staple cereal will be greatly cheapened. I shall be glad to renew "old acquaintance," by a more detailed statement hereafter.
I send enclosed the pay for another year of the SCIENTIFIC AMERICAN, which I can no more do without than my accustomed dinner.
C.
Madison, Wis.
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Economical Steam Engine.
Messrs. Editors:--Permit me now to make a few remarks in regard to an article on page 844, last volume of the SCIENTIFIC AMERICAN, entitled "Which is the Most Economical Steam Engine?" The principles laid down in that article, I think are correct.
I run a saw-mill with an engine which fills those conditions nearer than I ever saw, and I would like to give your readers a brief description of it. The cylinder is 10-inch bore, and 14-inch stroke; steam chest extends enough beyond the ends of the cylinder so that the steam travels only 2½ inches, the shortest distance possible, after leaving the valve before it reaches the piston-head, and the space between the piston-head and cylinder-head is only one-fourth of an inch, the bolt heads being counter-sunk until even. Other things about this engine are in proportion. With this engine attached to a direct acting circular mill, I can saw 2,000 feet of hard-wood inch boards in one hour.
If any of your readers can beat this, I would like to hear from them.
JOHN CARNES.
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Friction and Percussion.
Messrs. Editors:--In reply to "Spectrum," page 358, of last volume, I will be brief. In his third paragraph he claims that he has merely _suggested_ that friction and percussion may often be one and the same thing; and immediately claims that in the case of the polished button rubbing a planed pine board, the force which overcomes and levels the undulations of the wood, is percussion, and that percussion is also the cause of the heat; the microscopic hills and hollows on the shining brass button skipping and jumping along the pine, produces little infinitesimal bumpings, and so pound out the heat. This _little_ theory should be known to the homeopaths--they could illustrate infinitesimal quantities by it!
"Spectrum" treats my hammered horsenail illustration shabbily. After indirectly acknowledging that there is a point where hammering will no longer produce heat, he puts it on the grindstone, subjects it to friction, and when it burns his fingers, throws his hat in the air and shouts "Hurrah for _percussion!_" We agree perfectly, except that he calls hammering, _condensation_; calls friction, _percussion_; and drops friction from the mechanical dictionary altogether.
A railway car axle often heats and sets fire to the packing, when the journal is smooth as polished glass; but I never heard of those parts of the car which are constantly undergoing percussion, even getting uncomfortably warm. The natives of the South Pacific produce fire by rubbing pieces of dry wood together, but I never heard of their rapping sticks for the same purpose. I have seen a new, sharp knife made hot enough to raise a blister, whittling a clean dry stick of pine, and I would like to have "Spectrum" tell us, if in all the above cases percussion is the cause of the evolution of of heat, and what is friction doing in the mean time.
New Albany, Ind.
C.C.H.
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Oiling a Preservative of Brown Stone.
Messrs. Editors:--I have read the article entitled, "What is to Become of our Brown Stone Fronts," and have waited to see what others have to say. But with so much at stake, no body seems to know what to do or say. Being a practical painter, it has been my lot to oil some of the best fronts in New York, namely corner of 23d Street and 5th Avenue, No. 2, West 23rd Street, also No. 1, West 30th Street; also the residence of E.S. Higgins, the carpet manufacturer, done by other journeymen.
They were very dark in color for a few weeks, but now after two years, they are bleached almost as light as they were at first.
These fronts were cleaned whenever necessary, and then oiled with fresh raw linseed oil from the press, put on pretty much as carefully as in ordinary varnish work. No second coat or lapping over of the oil. All was put on at once that it would take without running down in streams.
The result: the oil penetrates into good dry stone probably 1½ inches, making the stone hard and flinty, as any stone cutter will soon find out if he tries to trim it.
It keeps the damp and therefore the frost out of the stone, as will be seen any foggy day, the damp running down in streams on the oiled stone, and the unoiled stone absorbing the dampness. It is therefore necessary to oil during dry weather.
The oil is especially beneficial to balustrades and carvings, as they are generally got out of soft stone. It is also beneficial underneath balconies and porches, as the sun never has a chance to dry the stone in such situations before the frost flakes it.
This I send in part payment for the great deal I have learned from your paper.
T.H. Rilley
New York City.
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Interesting Correspondence from China.
Messrs. Editors:--Your paper seems to increase in interest. I brought the back volumes from Madras to Pekin, and am glad to refer to them here where I must depend upon myself.
I have been building and repairing premises since I came here last year. I find the carpenters and masons are very much delighted with our tools, especially our saws, planes, borers, vise, and hammers. Our lathe is a wonder. They use only the ancient spindle turned backwards and forwards by a treadle or by the left hand while the right guides the chisel or turning-tool, which cuts only half the time. They use only the turning saw, which often fails them because it cannot be used in splitting wide boards in the middle, and in many other places. They are great sawyers, however. They stand heavy pine spars on end, if rather short, say 8 feet, the common length of many intended for making coffins, and cut them up into three-eighths or half-inch stuff with great patience. A longer one they will lean over and prop up, raising it towards the perpendicular as they advance. They must have some hard jobs. I have just measured a poplar plank in front of a coffin manufactory, which I found to be 5 ft. 3 in. at the butt, 3 ft. 10 in. at the top, 8 feet long, and about 8 inches thick. For a crosscut saw they rig one like our wood-saw. I am sure it would deeply interest you to make a visit to Pekin and see how this ancient, patient, and industrious people do their work. It is truly painful to see how much time they spend in making the simplest tool for want of at least a few labor-saving appliances. Doubtless you have their tools on show in New York. They are to me an interesting study, though I have been long familiar with the rude tools of the Hindoos. It is constantly suggested to me that we must have got many hints from the Chinese, or else indeed they have taken hints from the West; or again, which is perhaps the true solution, implements like words have a common origin. I should think from what I have observed in a short time, that the Chinese resemble the Europeans in their tools more than the Hindoos--a thing I did not at all anticipate. A clever man could write you an interesting chapter on the ways of the Pekinese, the Chinese Manchus, Mongols, and the rest mixed together, though the Chinese are confessedly the workers in wood, iron, and everything else. The Manchus are mostly hangers on of the government, living mainly upon a miserable monthly stipend.
The reading of your unequaled journal makes me interested in you as if you were personal friends, and so I have run away with these pointless remarks. I am sure you will excuse me, and not wonder that one wishes to breathe now and then.
I was an old subscriber in Madras, and hope to be till I can read no longer. My son, who perished at Andersonville, was a subscriber to the SCIENTIFIC AMERICAN till the day of his capture by Mosby.
Pekin, China.
P.R. Hunt.
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Communication Between Deaf and Blind Mutes.
Messrs. Editors:--In a recent number of the SCIENTIFIC AMERICAN I notice an ingenious method of teaching deaf and dumb persons to converse in the dark, which is also applicable to blind mutes, and it brings to my recollection a method which was in use among the "telegraph boys" some years ago when I was one of them. Sometimes when we were visiting and asked to communicate to a "brother chip," anything that it was not advisable for the persons around us to know, a slight tap-tapping on the table or chair would draw the attention of the party we asked to talk to, and then by his watching the forefinger of the writer, if across the room, or if near enough, by placing the hand of the writer carelessly on the shoulder of the party we desired to communicate with, the communication was written out in the telegraph alphabet or by taking hold of his hand and writing upon the finger.
I think this method will be found much less complicated, if not quite as rapid, as the method with both hands, and much more convenient, as it is only necessary to have hold of one hand of the person communicated with, and is more rapid than writing with a pen.
For the benefit of those not acquainted with the telegraph alphabet, I give it:
A B C D E F G H I .- -... ... -.. . .-. --. .... ..
J K L M N O P Q -.-. -.- --- -- -. . . ..... ..-.
R S T U V W X Y . .. ... - ..- ...- .-- ..-. .. ..
Z ... .
The uninitiated will observe that O differs from I in the distance between the dots, made thus: I by two quick strokes of the forefinger; O by one quick stroke, slight pause, and another quick stroke; the dashes are made by holding the finger down for a short space: thus SCIENTIFIC AMERICAN would be written:
S C I E N T I F I C ... .. . .. . -. - .. .-. .. .. .
A M E R I C A N .- -- . . .. .. .. . .- -.
In a very short time any one can learn to read by the sight or by the touch. Anything which can add to the pleasure or comfort of these unfortunates is of importance.
MAGNET
[Nothing can compensate for want of rapidity in a language designed for colloquy. Although our correspondent found the Morse telegraph alphabet a resource on occasion, he would scarcely be content to use it, and it only for life, even if emancipation from it involved months of labor. The motions required to spell SCIENTIFIC AMERICAN by the telegraph alphabet are thirty-nine, but as the short dashes occupy the time of two dots for each dash, and there are eight of these, eight more ought to be counted in a comparison of it with an alphabet composed wholly of dots, this would make forty-seven. To spell the same words in full by the mute alphabet referred to would require only twenty-three motions. A still greater disparity in rate would, we think, be found in an entire colloquial sentence. Thus the sentence "Hand me an apple" would require, by the mute alphabet, the time of fourteen dots, while with the telegraph alphabet it would require the time of thirty-nine.--Eds.]
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Cheap Cotton Press Wanted.
Messrs. Munn & Co.:--Please give us any information of cheap cotton-presses, such as small neighborhoods, or single planters, in the South could own. In particular, a press that will put 40 pounds cotton into each cubic foot. We want cotton better handled, and to that end may want small bales, say 150 pounds each. But these must be put into three or four cubic feet, or they will cost too much for covering, ties, etc. Perhaps you can furnish us with a wood-cut of some, or several, presses worked by hand, or by horse-power, that will do good service, not cost too much, be simple in operation, not require too much power, and be effective as above. It may be for the interest of some of your clients or correspondents to give us the facts, as we shall put them into a report for circulation amongst the entire cotton interest of the country.
Yours very truly,
WALTER WELLS, _Sec'y_.
National Association of Cotton Manufacturers and Planters, No. 11, Pemberton Square, Boston, Mass.
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A Singular Freak of a Magnet.
Messrs. Editors:--In my library hangs a powerful horseshoe magnet which has a keeper and a weight attached of about three ounces. This weight is sustained firmly by the attracting power of the magnet, and is not easily shaken off by any oscillating motion, yet through some (to me) unknown cause during each of the last ten nights the magnet has lost its power, and the keeper and weight lie in the morning on the bottom of the case where the magnet has hung for many years without a like occurrence, except once on the occasion of a severe shock of an earthquake which took place December 17, 1867.
There is no possible way for this magnet to be disturbed except by the electric current; then why should its power thus return without the aid of a battery or keeper? Will some one explain?
FLOYD HAMBLIN.
Madrid Springs, N.Y.
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Speaking makes the ready man, writing the correct man, and reading the full man.
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PRESERVATION OF IRON.
BY PROF. HENRY E. COLTON.
"What is wanted is something equally applicable to large or small pieces of iron, and which will answer to ward off the attacks not only of the common atmospheric oxygen, but also remain unaffected by acids or salt waters."
The above from a late number of the SCIENTIFIC AMERICAN states not only the writer's ideas but also one of the greatest wants of the age. Iron is daily being put to more and more varied uses. On land the great question is what will prevent rust; on water, what will prevent rust and fouling of bottoms of iron vessels. We will briefly summarize the many patents granted for this purpose.
Eight are for sheathing of various kinds put on in varied modes. The most practicable of these is a system prepared by Daft. Most iron vessels are now constructed by every other plate lapping the edges of the one between. He proposes, instead of having the plates all the same width, to have one wide and one very narrow plate. This would leave a trough between the two wide plates of the depth of the thickness of the plates. He proposes to force into this trough very tightly pieces of teak, and to the teak, thus embedded, he nails a sheathing of zinc. The zinc is kept clean by slowly wearing away of its surface from action by contact with the iron and salt water.
There are four patents, in which various, so-called, non-conducting coats are put on the iron, and copper pigment in some form put on over them. These have been specially condemned in England, as no matter how good the non-conducting substance--and many are so only in name--it will become rubbed off at some points, and there the bottom will be eaten both by salt water and action of copper.
Coal tar and asphaltum are the subjects of patents in various forms.
One patent claims rubber or gutta-percha dissolved in linseed oil as a vehicle in which to grind the pigment; another the same dissolved in naphtha or bisulphide of carbon as a pigment; another hard rubber, ground.
Enameling with different materials is proposed by some, while one proposes to glaze the bottoms so that barnacles and grass would find a slippery foothold.
Combinations of tallow, resin, and tar--mineral and pine--are patented mostly to use over other paints.
Coal tar, sulphur, lime, and tallow, are the subject of one patent; guano, red lead, and oil of another; while sulphur and silica are claimed by a third.
Paints containing mercury, arsenic, and even strychnine, are the subjects of several patents. A mixture of coal tar and mercurial ointment of one.