Mechanics' Magazine, MUSEUM, REGISTER, JOURNAL, AND GAZETTE. No. 107.] SATURDAY, SEPTEMBER 10, 1825. [Price 3d. "Were not genius and invention seconded by industry and perseverance, the brilliancy of genius would be merely the blaze of a passing meteor, and the cunning of invention would be rendered of no avail."-The Idler. 354 DIRECTIONS FOR TANNING-ENGLISH IRON. SIR SYDNEY SMITH'S SIX-WHEELED CARRIAGE. SIR, I now send you, as promised, the accompanying drawing of SIR SYDNEY SMITH'S newly-invented Six-wheeled Carriage, for the favour of a place in your useful Magazine, As I stated in my former communication (No. 87, page 37), its great advantage over the ordinary four-wheel carriage consists in the ease and facility with which it travels on any rough or uneven surface; and as it acts upon a principle of leverage, from its counterpoise motion on the centre wheels, it thereby preserves the body part from that uneasiness which any violent action of the extremities or end wheels, in their continued ascent or descent, on uneven pavements or bad roads, must otherwise occasion. It is, therefore, particularly adapted for the service of invalids and individuals requiring the greatest possible ease in their conveyance from one place to another. It is likewise of important utility as a military carriage, for conveying the sick or wounded, as it would give great relief to the sufferers, and tend materially to the preservation of life on long journeys and fatiguing marches, where the ground to traverse over is bad and unlevelled. As a sporting carriage, in crossing open countries, it possesses many advantages, for the body can be formed with seats to carry several persons, with every necessary convenience for containing dogs and game. The six-wheeled carriage can be constructed as a low phaeton, to be drawn by poneys, for the sick and invalid, the body part to swing on leather braces, and to contain a cot or couch to lie or recline upon, for the convenience of ease and support, as might be found necessary. As both pair of end wheels revolve laterally, the horses may be attached to either part of the carriage. Should any person be desirous of having a carriage on the six-wheel principle, every particular respecting it may be had by sending an address to No. 25, Bow-street, Long Acre. I remain, Sir, Your obedient servant, GM-. DIRECTIONS FOR TANNING. The following is copied from the manuscripts of the late Colonel Benjamin Hawkins : Green Hides. Take them immediately from the carcase to the pond, and let them remain twelve hours: then put them in lime. One peck of black-jack ashes to a hide, if large, or half a bushel to three hides. If the season is warm, in three or four days the hair will come; as soon as it will come, take it off. The first, second, and third day, work them well in the lime; do this by taking them quite out, and replace them; if necessary, add ashes, and always water enough to cover them. After they are haired, take them to the pond; the second and third day work each side well till the water or lime appears to ooze out of the hide of a dryish cast. The fourth day put them in beaten bark, so that no part of a hide lies on another bare. Here they are to lie nine days, and then be replaced in a second bark. Six weeks after, replace them in fresh bark, and let them remain in the tan. 1 Dry Hides. To be soaked in the pond, in warm weather, seven days; in March, nine days; seven days in lime, and seven to take it out for warm weather; in March, nine or ten; every thing else the same as for green hides. ENGLISH IRON. A very important discovery has been made for the improvement of this leading article of our manufactures and commerce, and the success TUNNELS IN ENGLAND THE STEEL-YARD. which has attended the experiments which have taken place must be gratifying in a national point of view. It may not be generally known that, in smelting iron in its original state, a great quantity of carbon and other impure matter is found, which is dissipated in the farther process in converting it into bar-iron. The more it is purified by the present process, the more it becomes soft and flexible, and is thereby rendered comparatively useless for articles where strength, toughness, and hardness, are required; and thus the manufacturer is compelled to use foreign iron in the construction of such articles. An individual connected with the iron trade, possessed of practical scientific knowledge, has devoted the greater part of his life to numerous experiments on the subject. Success has crowned his efforts, by the discovery of a process by which he can recharge bar-iron, or manufactured articles, with a mineral carbon, so as to give the softest iron a considerable portion of the steel quality, making it as hard as blister steel, without destroying any portion of the toughness it had before acquired, and this can be accomplished at a trifling expense on a large scale. It may be presumed that, by bringing English iron nearer in quality to the foreign, it will create a demand for our own production, and supersede the necessity of using the latter, which is gene. rally at a much higher price in the market. 355 The Leeds and Liverpool Canal has two tunnels, one of which is 1530 yards. The Leicestershire and Northampton Canal has four tunnels, of 286, 880, 990, and 1056 yards. The Leominster Canal has two tunnels, of 1250 and 3850 yards. The Thames and Severn Canal has one tunnel of 4300 yards, or two miles and 3-8ths. The Chesterfield Canal has two tunnels, one of which is 2850 yards in length. The Crumford Canal has one tunnel of 2966 yards, and several smaller. The Doudley and Owen Canal has three tunnels, of 623, 2926, and 3776 yards, or about four miles. The Ellesmere Canal has two tunnels, of 487 and 775 yards. The Hereford and Gloucester Canal, of 35 miles, has three, of 440, 1320, and 2192 yards. The Edgebarton Canal has four tunnels, of 100, 400, 500, and 2700 yards. The old Birmingham Canal has two tunnels, one of a mile and a quarter, the other 1000 yards. The Grand Union Canal has two tunnels, 1165 and 1524 yards. The Grand Junction Canal has two tunnels, 3045 and 3080 yards. The Oxford Canal has two tunnels, one of them 1188 yards.< The Huddersfield Canal, of only 19 miles long, with a lockage of 770 feet, has a tunnel of three miles and 1540 yards, through a rocky mountain. TUNNELS IN ENGLAND. The first Tunnel ever constructed in England was on the Trent and Mersey Canal, executed for the Duke of Bridgewater. It is about 2880 yards in length, and some parts cut out of the solid rock. The canal is 93 miles in length, and four other tunnels-131, 350, 573, and 1241 yards. The Worcester and Birmingham Canal, of 29 miles in length, has five tunnels; one of 2700 yards long, 18 feet high, and 18 feet wide; and four others 110, 120, 400, and 500 yards long. puzzled," for it must remain an everlasting puzzle, on the principle of weight being the effect of attraction; or, as W. X. says, "be it attraction or gravity." This case, with 356 SHAWL MANUFACTURE. many others, affords a demonstrative evidence, that no such principle exists as attraction; nor can all the mathematicians in the world elucidate the phenomenon, by the hypothesis that weight is the consequence of attrac-, tion. When the steel-yard is in equilibrio, with twenty pounds on one arm, and one pound on the other or longer arm, then, and in opposition to the theory of attraction, one pound is attracted to the earth as forcibly as twenty pounds; or, the weight of twenty pounds is not attracted more strongly than the weight of one pound. On the contrary, did the earth attract either, and according to their quantities of matter, both would be pulled by the earth towards the surface, and each with a force proportional to its quantity of matter, which would make the greater preponderate. Hence it is manifest that weight is not the consequence of attraction, as the equilibrium, under these circumstances, would be an impossibility. It is well known that one pound will balance twenty in an opposite scale, both scales being suspended from a beam of equal arms, provided it be let fall into its own scale from a sufficient height; in which case, as soon as the one pound strikes the scale, the scale with the twenty is lifted up, and the beam is brought to a horizontal position; and as long as that position is maintained, the one is as heavy as twenty. Hence it may be reasonably inferred, that as motion creates weight, and "more causes than what are rational, and sufficient to account for phenomena, should not be resorted to," weight is the effect of motion universally. Again, as attraction of the earth for a certain quantity of matter must be considered a fixed quantity, acting on it inversely as the square of the distance, it should be the fact, that the momentum of a falling body is always the same at the end of the fall, no matter the length of descent. For it is highly irrational to imagine, that the motion of a falling body is the cause of the increase of that motion; and the body could be attracted at all heights, only as its distance from the earth. The customary phrase, "the effects of motion re- I remain, Sir, SHAWL MANUFACTURE. Accidental circumstances lately called our attention to some facts connected with the history of the shawl manufacture, a short statement of which our readers may perhaps consider not without interest. We need scarcely state, that this species of manufacture has risen almost from nothing within the last thirty years, and that little more than twenty years have passed since it was established in this city, which may now be considered as the chief seat of the finest, though not the most extensive, branch of the manufacture. Shawls were originally made in the East Indies, and they exhibit a curious example of the high perfection to which some single species of manufacture may be carried in a country where the arts in general are in a rude state. So highly are these India shawls prized in this country, that they fetch a price of 100l., 2001., or even 500l., while the best of those of domestic manufacture can be had for 201. or 30%. But what makes the preference shown to the foreign_article the more surprising is, that no small proportion of the India shawls brought to Britain have been worn by the natives as turbans, girdles, &c. before they were imported. This is no secret SHAWL MANUFACTURE. among dealers, for the marks of wearing are often manifest to an experienced eye, in the discoloration or roughening of the surface, the attenuation of the fabric at particular places, and now and then in actual rents and holes, Strange as it may seem, therefore, it is literally true, that our wealthy and titled dames are content to array themselves in the cast clothes of our Eastern subjects, which vestments, notwithstand ing, have no small intrinsic value ! There are two substances of which the body or fabric of fine shawls is made-silk and wool. Silk has generally been employed in Britain; but the Hindoos use an extremely fine wool, and from the use of this material the India shawls derive much of their superiority. First, it gives them an exquisite softness and warmth, to which it is impossible to approach when the fabric is chiefly of silk. Secondly, the fine wool takes a brighter colour than silk, and keeps it incomparably better. Thirdly, the woollen fabric has an advantage which is perfectly understood by the ladies; its folds dispose themselves in more graceful and flowing lines, and of course it affords a finer drapery to the figure. With regard to the patterns, it must be admitted, that till we have discovered the mode of working the figure practised by the Indians, and till our weavers can subsist on twopence a day, and spend three or four years' labour on a single shawl, we shall scarcely be able to rival them. In the brightness of the dyes we already surpass the Hindoos, and the figures on their inferior shawls, which are sewed in or embroidered, are not nearly equal to the best of those which we execute in the loom; but in the finest of the India shawls the figures are wove in a manner which we cannot perfectly imitate, and of which our weavers only comprehend enough to perceive, that it must be extremely laborious and infinitely tedious. Indeed, it is certain, that even the smallest compartment of the figure must be worked on the principle on which we work an entire web-that the weft must be turned at each margin of the compartment, 357 though it should be but a tenth of an inch in breadth. The best idea we can form of the process may be derived from the mode of laying in the figures of tapestry; and hence, too, the Indian mode of working enables them to sink the ground of the web more completely, and to exhibit the colours of the pattern in a more unmixed state than we possibly can. It is remarkable, too, that long practice has taught them to combine their colours with singular harmony, and to diversify their designs, without falling into extravagance or incongruity, to such a degree, that the British manufacturer, with all his skill, finds it the best policy to copy their patterns, because he can seldom invent any thing better himself. In the execution of the figures, however, our manufacturers have made great progress within the last ten years; and this is not now the department in which their work has been felt to be most deficient. Latterly their leading object has been to rival the Indians in the fabric or basis of the web. Organzine silk was the material originally employed for warp, and upon this a weft of wool and silk, or of various mixtures of the two substances, was thrown in. This was succeeded, about 1804 or 1805, by spun silk, that is, the waste of Indian silk chopped into short lengths, and worked upon the same principle as wool or cotton-a process long kept secret, but now well known. It was made to resemble the Indian yarn very closely, and was deservedly considered a great improvement, though it still wanted the best properties of fine wool. Some years afterwards another step was made towards the introduction of the proper material, by preparing aweft of silk and Merino wool, which received the name of Persian yarn. This still continues partially in use. At length, about three years ago, an attempt was made to make the fabric of wool entirely. To the substance employed, the name of Van Diemen's Land, or Indian, or Thibet wool, was given, though in reality it consisted merely of picked quantities taken from picked Saxon or English fleeces. Of this a fabric was |