Imágenes de páginas
PDF
EPUB

DESCRIPTION OF THE IMPROVED AXLES AND WHEELS, Invented by JAMES AIRD and JAMES DUNLOP, Ayr Colliery; and for which a Premium of Seven Guineas was voted at last Meeting of the Highland Society.

To the Editors of the GLASGOW MECHANICS' MAGAZINE. GENTLEMEN,-We beg to send you a description of the axle and wheels which we invented for the use of the coal waggons plying upon the rail-way belonging to Messrs. Taylors, of this Colliery, and given in by us to the Highland Society of Scotland, by whom we have been awarded a premium for our invention. We likewise enclose you a drawing of the axles and wheels, with a description of the same.

Fig. 1, represents the axles and wheels, when full mounted, ready for attaching to the waggon. A,

the iron axle; B, the wooden bed of the axle; C, the ruff in the wheel; D, the collar which goes into the ruff on the wheel; E, the catch, or sneck, which prevents the collar from flying out of the ruff on the wheel.

Fig. 2, represents the axle.

Figs. 3 and 4, represents the wheels.

Figs. 5 and 6, represents the collar for securing the wheels to the axle.

If you deem the enclosed drawing and description worthy of at place in your Magazine, it may

[merged small][merged small][ocr errors][merged small]

perhaps be the means of suggesting ideas of more improvement upon this subject, and your insertion of the drawing and description will very much oblige,

GENTLEMEN, yours, &c.

JAMES AIRD.
JAMES DUNLop.

Ayr Colliery, 7th Feb. 1825.

GENTLEMEN, The axles and wheels, as per the enclosed drawing and description, have been in use upon our rail-ways here for about nine months; and we have found, in using them, a great saving in grease, and the friction much lessened from the sand and dust not getting into the axle. The waggons are, therefore, much easier drawn; so much so that we are now engaged in fitting up our small under-ground waggons upon the improved plan; and, as the waggons now in use upon the old plan wear out, we re-fit them upon the improved plan, and have now at work forty waggons upon the improved

construction.

[blocks in formation]

PRINTING PRESS.

these arts, meets your approbation, you can give it a place in your Magazine.

Fig. 7, represents a stout table, the top of which is made of boards 1 or 2 inches thick, and which is equal in breadth and length, and double in both to the breadth of the board of the press, press. The upper upon which the fulcrums of the levers are fixed, is supported 11 inch from the top of the table by

two thin pieces of wood, a, c, placed on edge, and is surrounded on the sides E D, D F, and F G, by a stout border, the height of which coincides with the top of the board when it rests on the pieces of wood a, c. The border is also continued along the sides E B, and G H, but these rise only one inch above the top of the table. The fulcrums differ from Mr. North's only in having a hole through the top for the levers to pass through, instead of lying upon them, in order that when the longer arms of the levers are pushed up they may carry up and suspend the board by the fulcrums. From the ends of the levers b, b, are suspended iron rods, f, f, which are connected together by the bar i, and are bent to remove the bar i farther from k, where the lever k, m, is fixed to the bar of the table.

Fig. 8, is a board half an inch thick, nearly the same size with A, having a bracket, three-fourths of an inch thick, firmly fixed along its sides B A, and D C, with a handle at h. This board is designed to carry the types, stone, &c. which must be placed between the brackets, and wedged between them. It must have also attached to it an iron frame, D, F, G, C, covered with leather, to fold down upon the types after the paper has been

placed upon them, to prevent the paper being deranged when the board is pushed under the press.

To use this machine, the board with the types, &c. is placed on the half of the table E, H, and the ink applied to the types. The foot of the operator is then to be placed at o, on the lever n, o, and o pressed down till the other end of the lever has, by lifting up the bar i, raised the levers b, b, till A is suspended so high that the board with types, &c. can slide easily below it. The foot is then to be removed, and applied to press down m, which will produce a strong pressure upon the types. If we suppose the long arms of the levers, b, b, to be to the short as five to one, that i is fixed in the middle of k, m, and that a weight of 100 lbs. is applied at m, A will be pressed upon the types with a force equal to 1000 lbs. independent of the weight of the board, levers, bar, &c. Presses of this kind might be made larger than Mr. North's for I think about three times his estimate, and I at present know no reason why they should not answer the purposes I propose them for well, though I must own myself unacquainted with the practice of these arts.

I am, GENTLEMEN, yours, &c.

M. N.

FARTHER IMPROVEMENTS ON THE WATER TRAP.

To the Editors of the GLASGOW MECHANICS' MAGAZINE, GENTLEMEN,It seems to be a prevalent opinion, that the effluvium rising from common sewers, through the gratings, in this and other large towns, is injurious to health-which opinion is probably well-founded. The question then is, what is the most simple and effectual contrivance for preventing it? and, at the same time, allow

ing the water from the gutters to fall freely into the sewers?

Simplicity and durability is absolutely necessary in things of this nature they must not be liable to go wrong, nor even to be put wrong. Without saying any thing on the plans that have been proposed, I submit the following to those who take an interest in the improvement -than which at least I can conceive nothing more simple.

A, B, C, D, (fig. 9,) is a curved trunk, or tube, open at both ends; A, B, is the grating covering its upper end, with which the lower end makes an angle of 45 or 50 degrees, and which is provided with a valve, C, D, having hinges, with a tail, so as to clear the outlet entirely, when raised to prevent straw or other matter from lodging about the joint. This valve, by reason of its angular position, bears on the end of the tube with about half its own weight, and is thereby kept close when once accurately fitted. The weight of the valve may be easily adjusted to sustain the pressure of a small quantity of water, suppose to the level of E, F; but, when the water, by running through the grating, rises a little higher to G, H, it will raise the valve and fall into the common sewer. It will be observed, from the position of the valve when open, and the form of the tube, that nothing can possibly lodge to prevent it from falling

close on the orifice when the water ceases to flow through the grating. The hinge, or joint of the valve, ought to be brass, to prevent stiffness from rusting.

It is a pity that the inhabitants of large towns should be assailed by noxious vapours for want of such a simple apparatus. Indeed, except the valve, it is no more than a plain cast-iron water-way; which, for its very look, would be a great improvement, instead of the dirty rubbish of stones seen at present through the gratings. If those whose duty it is to remove nuisances, and promote the health and comfort of the inhabitants, thought of adopting the improvement, their best plan would probably be to make trial of one of each of the two most approved that have been suggested; and, after deciding which was superior, they could with more confidence bring them into general use. G. M.

Glasgow, 2d Feb. 1825.

ON THE MODE IN WHICH THE SYPHON ACTS.

To the Editors of the GLASGOW MECHANICS' MAGAZINE.

GENTLEMEN,-Having observed, in a former Number of the Magazine, a remark concerning the usual explanation given of the action of the syphon, implying that it is not quite convincing, I offer the following, which will be found to be more satisfactory-although the usual explanation certainly shows that an equilibrium does not exist, and therefore motion must take place.

Let A, C, (fig. 10,) be a vessel filled with water to A, B. D, E, F, a syphon; and, for simplicity, let the column of water, D, E, or E, L, be equal to the atmospheric pressure, and let G, D, and F, K, be two columns of atmospheric air, of the same diameter as the syphon.

Then the atmospheric columns G, D, and M, K, support the columns of water D, E, and E, L. There remains, therefore, only the atmospheric column M, F, to support the column of water F, L; and, of course, F, L, will preponderate, and its place will then be occupied by another quantity of water, and a continuous flow will succeed.

The same reasoning will apply when the columns of water, D, E, and E, L, are less than the atmospheric pressure. For the excess of the pressures of the columns, G, D, and K, M, above D, E, and E, L, being equal, and acting in opposite directions, destroy each other's effects, and hence the result must be the same as before.

Dollar, 28th Jan. 1825.

A. B.

TAXIDERMY;

OR,

THE ART OF PRESERVING OBJECTS IN NATURAL HISTORY.

THE art of preserving animals has received the name of Taxidermy -being composed of two Greek words, rais order, and digua the skin.

There is nothing better calculated to refresh the memory, to furnish standards with which newly discovered objects may be compared, and to excite an interest in the study, than a collection of objects in Zoology well preserved. No mere verbal description, however accurate, is sufficient to convey a correct idea of the characters of an animal. Many relations of parts, and many gradations of form, may be perceived by the eye, which words are unable to express. Even drawings fail in conveying an accurate idea of the form and other external characters. Coloured drawings of animals are eagerly sought after. Yet how seldom are they accurate; and, even when they are, they form the least important character that is employed. Besides, there is a great risk of errors being introduced in the course of the engraving, in order to suit professional taste.

The art of preserving animals is of recent invention, having only made any progress during the last 60 years. The first writer on the subject was the celebrated Reaumur, who published a memoir on the method of preserving skins of birds to be sent to a foreign country. It was sufficiently simple. Having received the bird preserved in spirit of wine, he contented himself with taking it from this liquor, and introducing two ends of an iron wire into the body behind the thighs. He then fastened the wire to the claws, fixing it in a small board, and put two black glass

beads in the place of eyes, and called it a stuffed bird.

The next improver of the art was Schoeffer, who, after skinning the bird, contented himself by cutting the birds longitudinally in two, and filling one half with plaster. He then fixed the skin to the back of the box, stuck in an eye, and represented the beak and claws by painting. This method is still followed in Germany, though much improved.

The next that we have to mention is the Abbé Manese, whose work appeared in 1786. Though not the inventor, he was the first that recommended, in print, the method of preserving animals which we at present pursue. The principal objection to his plan is, that he adopted the use of alkalis for the purpose of destroying insects. There is no doubt but that they

may fulfil the purpose of preservation, but they are very apt to deliquisce and attract humidity, to such a degree, that in wet weather the bird is kept in a damp state, which must soon prove destructive to the beauty of the plumage and even to its existence.

Manduyt followed him, in a memoir on this subject, in the Encyclopedie Methodique. The rules he has laid down are of considerable importance, being an improvement on the plan of the Abbé. He has not, however, pointed out any means of preservation, with the exception of employing sulphurous fumigations for the purpose of killing destructive insects. This, however, is a pernicious process, injurious to the specimen, the skin in many places wrinkling, or being destroyed, and the colours of the feathers suffering important changes.

In 1802, Fontenelle published a paper on this subject. The plan he proposes, however, is too tedious. The only preservative he recommends is the oil of turpentine. This, however, is found not to answer the purpose, the feathers, unless they are soaked in it, soon becoming affected with insects; and even when it succeeds, the preservation is always at the expense of their colours, the feathers soon absorbing the turpentine, and becoming tarnished.

The last foreign author we shall notice is M. Dufresne, whose small work on Taxidermy has been translated into English, and gone through several editions, being by far the best on this subject.

There are but few writers on Taxidermy in our own language. There is a small tract by Mr. Swainson, of Liverpool, of no great merit. There are also several judicious remarks in Dr. Fleming's Philosophy of Zoology.

Instruments and other Articles.

1. An assortment of softened iron wires. 2. Flax or tow, or the ends of untwisted cords. 3. Scalpels, scissors, and forceps. 4. Pincers of different kinds. 5. Hammer. 6. Two files. 7. A collection of eyes. -As for

Preservatives,

different substances have been proposed. Mr. Warrington recommends a solution of corrosive sublimate in spirit of wine, to be brushed over the inside of the skin, and over the feathers. Although this is effectual in preventing the attacks of vermin, it does not secure against the progress of putrefaction until the specimen is dried. To remedy this evil, some applied it in the form of a dry powder, mixed with equal parts of burnt alum and powdered galls. This serves both

as a security against insects, and also facilitates the drying of the specimen; and, when it is completely dried, it may bid defiance to insect foes. Quantities of musk and camphor are sometimes added. But they may readily be dispensed with, since they are not necessary to the future preservation of the specimen, and they add materially to the expense.

Arsenic, however, has in a great measure superseded corrosive sublimate, since the latter is found to destroy the wires employed in preserving the form of the specimen. The best form in which it can be used is in that of the arsenicated soap.*

In the chace, a double-barrelled gun is to be preferred: one of the barrels loaded with small shot, for the little birds; and the other with

large shot. The former ought also to be loaded with much less powder than the latter. When the animal is shot, we ought to sprinkle some dry dust on the wound, and introduce some lint into the mouth, to prevent the feathers being soiled with the blood. We are then to allow it to remain undisturbed till it is cold, and then convey it home, disturbing the feathers as little as possible. When the animal is obtained alive, we are to kill it by pithing-i. e. introducing a sharp instrument between the skull and the first vertebra, so as to divide the spinal marrow. In small animals the puncture of a needle will be sufficient. In summer, the animal should be skinned on the day * White oxide of Arsenic Soap

Salt of Tartar Quick-lime

Camphor

[ocr errors]

each 2 lb. 12 oz. 4 oz.

.................

5 oz.

The whole beat up into an uniform mass. To be dissolved by water, and applied by means of a common brush. This is the application employed in the Museum of Paris.

« AnteriorContinuar »