Page:Scientific American - Series 1 - Volume 001 - Issue 03.pdf/2

 —We thank our kind patrons for their promptness: but would remind those few who have received the second number of this paper, but have not yet sent the first dollar according to stipulation, that promptness in this case, is essentially important to us. We trust they will save us the trouble of calling on any one by name.

—It appears to be the wish of many of our subscribers, who have not had the perusal of the "New York Mechanic," that we should insert in this, some of the most interesting articles from that paper. We trust our former patrons, who have seen those articles before, will not regret their insertion.

—We have a few copies of our first number remaining, and those who intend to become subscribers will do well to secure them while they may. There will soon be a pressing demand for them, when too late.

—We have on hand a variety of scientific matter, and interesting intelligence of railroads and other subjects, which, together with the music prepared for this number, are unavoidably deferred.

and others to whom this paper may be sent, are respectfully solicited to exhibit the same to others, that its patronage may be thus extended.



In pursuance of our subject, illustrating the laws and effects of gravity, we have placed at the head of this article a representation of a miniature image, balancing on the point of a needle or pointed spindle, and holding in each hand a common table fork. We have selected this simple mode of illustration, that our juvenile readers may find the means of experimenting on this important point of natural philosophy, completely within their reach. It will be seen that one tine of each fork is fixed in one of the hands of the image, and the handles or helves descend some distance below the feet so that if the body of the image inclines in one direction, and consequently are elevated or raised somewhat higher than when the image stands upright. How the helves of the forks being supposed to be made of iron, while the image is lightly constructed of light pine wood, the said handles preponderate over the image, and by their superior weight, hold the image in an upright position, as represented above. In this instance the force of gravity, by causing the heavier parts of the apparatus to seek the lowest possible position, elevates the lighter part,—the body of the image. And the figure is held in its present position, by the equality of the force which gravity exerts on each helve; for it will be readily seen, that if one fork approaches the spindle, the consequent elevation of the other, is greater than the descent of the first can be by this movement. And as neither of the helves have any direct tendency to approach the spindle, only as that by so doing they gain a position a little nearer the earth, it cannot be supposed that either of them, by approaching one inch nearer to the earth, could force the other two inches farther from it: but, on the contrary, if one could be indulged with two inches perpendicular descent, at the expense only of elevating the other one inch, it would readily do it. And this would be the case if one of the helves were forced down to the spindle, and then let go: the other would preponderate, and both, after vibrating awhile, would rest at their present position, and always at the precise point, at which the action of gravity on each becomes equal, thus mutually accommodating each other.

If this image with the forks he put in motion rotarily, the motion will be continued by inertia, until the resistance of the atmospheric air, united with that of the friction produced by the motion of the foot of the image on the point of the spindle, shall have become equal to the force already applied to produce the said motion. And during the whole of this process gravity will have maintained its ascendency by supporting the upright position of the little wooden man.

We may here remark, however, with regard to the force of gravity, that it is not wholly directed towards one point, or in one direction. The whole earth (to say nothing of other bodies) attracts each particle; and each part attracts each. Consequently, a body on the surface of the earth is attracted not merely downward, but horizontally in all directions. But as the greatest quantity of earth is in the direction of its centre, and as the attractions in all other directions are balanced by each other, the effects of their united attractions are precisely the same, as if this force was exerted in only a vertical direction; and this brings us to the subject of Equilibrium. (To be continued.)





’ Improved Patent Iron Truck for Rail-Road Cars, is presented above, and the attention of Rail-road Companies is respectfully invited to the following description of their justly-celebrated invention:

Figure 1 of the drawing above represents a top view or plan of this Improved Rail-road Truck. Figure 2 is a central, longitudinal, and vertical section. C, Fig. 1 and 2, represents the arched bars of the side trusses: they consist of two long bars of plate iron, (about three inches wide by seven-eighths of an inch thick,) bent into the shape as seen in drawing 2. Each of them is placed directly over a flat and straight tie bar, A, which extends from one end to the other, as seen in Fig. 2. These parts, so arranged, receive between their ends the ends of diagonal cross bars or braces, B, which are united at their centres by being clasped and welded, as seen in Fig. 1. The bars so composing what may be considered as side trusses and diagonal cross braces, rest at their ends upon four pedestals, F F, which receive the bearings or boxes for the wheels to run on, Another flat tie bar, P, extends from the under side of one of the pedestals to that of the other, on the same side of the frame, and the whole is secured together by eight bolts, J J, passing down through the ends of the several bars, A B C, and the pedestals, and on each side of the journals of the axles, O O, in the positions represented in the drawings. From the above it will be seen that there are two bolts to each pedestal, and that this number is all that is requisite for the full security of the bars and pedestals together. The body rests and moves upon two sectional supports, D D, arranged on the sides of the truss frames, as seen in Fig. 2: they extend somewhat, or a sufficient distance above the truss frames, and are jointed at their lower ends by means of the bolt, L, which rests upon the top of the lower spring, M, which spring rests upon a bolt passing through the lower part of the inverted strap, E, which strap passes over and rests upon the top part of the upper spring, M, which is placed within the truss frame, and rests upon the top of the bar, A. Two bands, N N, are placed entirely around the central part of each truss frame, the object of the same being to transfer the strain, or a portion thereof, of the spring, from the tie bar, A, to the arched bar, C.

These Trucks are adapted as well for eight-wheeled passenger cars as for baggage and freight cars, giving to each a more agreeable and easy motion than any other Truck heretofore constructed or in use. They are simple in their construction, combining strength and great durability, although weighing at least twelve hundred pounds less than the common Trucks. Besides these excellences, by reason of the elasticity of the braces, B B B B, as seen in the drawing, and the other peculiarities of construction, the weight is equalized upon all the wheels, and yet any one may be raised so as to pass any inequality on the rails without lifting either of the other wheels from the track, thus rendering it almost impossible to run a car off. Being bound, and having ar it [sic] were but four joinings, they are protected from injury by lateral strains, and in case of damage are easily repaired.

— Take any quantity of nitro muriate of gold, and evaporate by exposing it to a gentle heat in a glass tumbler or phial; the gold will form itself in crystals on the bottom and sides of the vessel; collect these crystals and dissolve them in ten times their weight of pure water. Then put a gill of water into a common flask, and add one ounce of granulated zinc, and one fourth of an ounce of sulphuric acid. Hydrogen gas will be evolved, and rise through the neck of the flask, which must not be stopped. Immerse a piece of white silk in the abovementioned aqueous solution of gold, and expose it, while wet, to the current of gas as it rises from the flask; the gold will soon be revived, and the silk will become beautifully and permanently gilt. Any letters or flowers may be drawn on the silk with a camel-hair pencil dipped in the solution, and on being exposed to the action of the gas, will be revived and shine with metalicmetallic [sic] brilliancy. The silk must be kept moist with water till the gold is revived. Zinc may be prepared for the above purpose, by melting it, and stirring it continually with a stick or iron rod while it is cooling; or it may be pulverized with a hammer as soon as it becomes solid.

—Proceed as directed in the last experiment, only use the nitrate of silver, instead of nitro muriate of gold. The process of crystalizing, redissolving, &c., is the same. But the crystals of silver differ in colour, being white, whereas those produced from gold are yellow. If a jar or box be filled with hydrogen gas, and the silk [sic]usspended in it, the action of the gas, and consequently the revivification of the metals will be more uniform. For small figures, however, it may be as well to fix a stopper in the flask, having a small orifice through it, that the gas may be thrown with some force on the silk and will have a more certain effect. A solution of muriate of tin may be managed in a similar manner, but none of these solutions can be thus revived on paper.

—It is estimated that no less than 400 tons of nails are manufactured and used daily in the United States. This would amount to about 48,000,000 in number, allowing 60 to the pound, which would be 4,000,000 per hour, allowing twelve hours for a day's work; or 66,666 per minute; or 1,111 per second;—sufficient to give constant employment to 3,000 carpenters with their hammers, to drive them. What a clattering would there be if they were at work all together.

—Paint any picture on paper in the usual way, only instead of colours use the following substitutes: for green, use a solution of nitro-muriate of cobalt—for blue, a solution of sulphate of iron—for, a solution of nitrate of bismuth—and for a brown, a solution of sulphate of copper. Any of these solutions may be more or less diluted, as the respective parts of the picture are to be light or dark, but none of them must be strong enough to colour the paper. This picture is invisible: but when it is required to appear, the paper may be tacked up on the wall, and having a glass of the transparent solution of prussiate of potass, (which by sight cannot be distinguished from clear water,) dashed suddenly upon it, the picture will instantly appear in its full colours. A similar effect may be produced by drawing the picture with infusion of galls, and subcarbonate of potass; this is revived by a solution of sulphate of iron, and appears in a yellow and brown colour.

—Dissolve equal parts of sulphate of copper and muriate of ammonia in water, and write. When you would make the writing appear, warm the paper gently by the fire; the writing will appear in a yellow colour, but as soon as you take the paper into the cold air, the writing will vanish. This may be often repeated.

—The survey of the route for the Telegraph from New-York to Baltimore, has been made as far as Norristown, Pa., via. New Hope and Doylestown. It is contemplated to continue the line direct to Baltimore, with branches from Norristown to Philadelphia and other places. The line from Albany to Utica is rapidly progressing. The posts are already on the ground ready for erection, as far as Little Falls. A part of this line will go into operation in a few days.

We intend giving a description, and explaining the principles of this invention, in a few days; but must first introdnceintroduce [sic] and explain the principles of galvanism and electro-magnetism. We shall arrange the branches in order and to the best advantage.

—The first paper that reached our table, under our new organization, was the "Democratic Pharos," of Logansport, Ia. edited by S.A. Hall. We have seldom found a more interesting variety of intelligence in a paper of equal size, than in this. Mr. Hall is entitled to our thanks for so early attention.

There is something peculiarly fascinating in the art, or at least in the practice of painting, and few if any can be found, who have not a fondness for it. Plain painting appears very simple in its process, and thousands of people, without either instruction or experience in the business, have ruined the appearance of their rooms, doors, carriages, &c., by attempting to paint them, instead of employing a workman to do it. In such cases the amateur usually procures a little paint, ready mixed, at a shop—not considering that no painter can know how to prepare and temper a colour properly unless he is acquainted with the state and circumstances of the work to which it is to be applied,—and having borrowed a brush for the purpose, he applies the paint with all the skill that nature has given him: he is delighted to see how readily he can produce a change of colour, and perhaps succeeds very much to his own satisfaction; but yet leaves it in a state that will not only readily appear decidedly ridiculous to every beholder who is acquainted with even the first principles of the art, but that will defy the skill of the best painter to make the work look decent ever afterward. To remedy these evils, and enable every reader to indulge himself in the occasional employment of painting for his own amusement or convenience, and to enable ordinary practitioners in the art to attain to higher improvements, and embrace a more extensive knowledge of the various branches, are our main objects in presenting a series of instructive essays on this interesting art.

To commence with the first principles of painting in its most simple form, we have only to procure a dilute mixture of white clay, red or yellow earth, (called ochres,) or of ground charcoal and water; and spread it over the work to be painted, with a sponge, or a bunch of moss or grass. The idea readily occurs, however, that this paint would become more permanent, by the addition of a little glue, or mucilage of any kind. This art of painting in water colours has been brought to great perfection by means of well-formed brushes of various sizes, and a great variety of fine and beautiful colours and is much in use for painting walls of rooms, plain or figured; also, panoramic scenery, and a great variety of ornamental work. This painting, when the colours are properly tempered with glue and certain other materials, becomes hard and durable, if not exposed to water or moisture; but it is of no value on work that is exposed to the weather, or that often requires washing. We shall now leave the subject of painting in water colours—to be resumed in a future number—and proceed to the more important subject of plain painting in oil colours, or with paints ground in oil.

The principal paints used in oil painting, are white lead, yellow ochre, chrome yellow, chrome green, French green, red lead, red ochre, Venetian red, vermillion, lake, Prussian blue, ultra-marine, lamp-black, and ivory black. There are twenty or more other colours, diverse from the above and from each other; but these can hardly he said to be in common use.

(To be continued)

—The Phildelphia papers describe an elegant little invention; about the size of a large pencil case. It contains a pen, a pencil, and a tooth-pick; and being unscrewed in the centre, displays a balance for weighing letters, from one-eighth of an ounce to two ounces, with the price of postage marked on the margin. The price of this combination of utilities, is 50 cents.

—A machine has been put in operation at Chicago, Ill. for boring iron and steel; and is reptesentedrepresented [sic] by the Prairie Farmer, as requiring only the power of one man to bore cold iron as rapidly as wood is bored by an augur. There is considerable appearance of absurdity in the statement however, although the invention is probably very valuable.

—A machine has been for some time in operation, in Geneva, the performance of which is highly spoken of, [sic] It is driven by two horses, and with the attendance of a man and boy, cuts the grain, leaving it in good order for binding, as fast as ten men can bind the sheaves. It will cut about twenty acres per day. The machine was invented its Maryland, and costs about 100 dollars.

—An invention is announced in some of the European papers, as having been exhibited at St. Etienne, and by which a pure transparent glass is produced, which is susceptible of being bent in any form while cold, without breaking. This production is called silicon, and appears likely to prove an invaluable acquisition to the arts and trades.

—We are elated, and withal affected, with sensations of deep gratitude, by the ready responses and friendly notices, of so many of our most highly esteemed cotemporaries; and especially by the appearance, in many of our exchanges, of our advertisement, at full length. Had we entered the editorial ranks as a political partisan, we should have expected the greetings of political journals of the same stamp, as a matter of course. But the case is far otherwise; and we know of no motive, but that of goodwill, or of courtesy refined, that would have procured so prompt and extensive favours. Friends, we thank you; and should we not have opportunity to reciprocate these favours, it will not be through any deficiency of disposition on our part. To those of our exchanges who insert our advertisement we shall send duplicates; and if by any means any of those should fail of reaching their destination, we hope to be informed thereof that the missing numbers may be promptly supplied.

There are said to be about 14,000,000 of the white population of the United States employed in agriculture, and only 500,000 mechanics and manufacturers.