morala would be deteriorated-and they would be discontented with the govern ment. At the time when large meetingsTM took place at Manchester and elsewhere, deputies from the radicals had, no success among the Spitalfields weavers, who being fairly paid for their labour, would have nothing to do with politics.

Mr. Hale, on being cross-examined, admitted that he had lately reduced some of his weavers to three-quarters work, and stated, that a variety of circumstances, as to the quality of the silk which could not be known till it was wore, or injuries it might receive in the progress of the mai u facture, all fell on the journeymen weavers, were a bindrance to them, and occasioned them, though sometimes paid at the rate of 25s. or 26s. per week, not on an average, even the best men, to make 20s, por week all the year round. Some of his workmen do not earn above 6s. or 7s. per week. No reduction in the price of any one article, or kind of work, since passing the act of parliament. Under the operations of this act, the Spitalfields weavers have been more constantly in work than those of any other part of the kingdom. The silk manufactory is carried on by people who have not much capital. Soveral manufacturers have not above 100l. which renders them, in case of a sudden rise in the price of provisions, incapable of employing all their hands. Such persons have generally been weavers, keep ten or twenty looms, have raised them. selves by their own industry, and are many of them an honour to society. It depends, in some measure, on the quality of the article, whether men make more or less money, though the rate is fixed. Journeymen could earn more money when wages were first regulated than they can

now.

On being examined by the committee, Mr. Hale stated, that the proportion of plain work as compared to figured, had increased in Spitalfields, and he attributed the country working more figured silks, to the circumstance of their being better paid for than the plain. Repeated his statements, that not so many journeyinen weavers received parish relief, as journeymen of other trades; and, also, that when a man receives parish relief, he is a lost man His proposition to reduce the wages in the manufactory of figured arti cles not listened to by the other masters. Whenever he has met the journeymen, found them tractable. Weavers of figured work, though sometimes gaining more money than weavers of plain-would be glad to have constant employment in the

latter. Figured articles are paid pro portionably higher than plain ones; be cause, when the price for making figured articles was fixed, it was customary to change the pattern once every forty or fifty yards, but now the same pattern is used for some thousand yards, which is a great advantage to the weaver, and is the reason why such kind of goods are more manufactured in the country, where the rate of wages is not fixed, than in London where it is. Imitations of poplins may be sold for 16d. per yard, and are put in the price book at 15d. for weaving. Those shot with worsted, though not requiring half as much labour as those shot with silk, are paid for at the same rale.. This wants regulation. Articles are made at Manchester and Macclesfield to imitate the Spitalfields ones, at a much less price, but which are not half so wearable or lasting.

[To be continued.]

REFRACTION OF RAYS.

When the Russian voyager Golownin visited Japan, the natives displayed insatiable curiosity about the books be longing to the voyagers, and there was no end to their inquiries respecting their contents. The Physics of Libes, with the imperfect mode the parties had of communicating their ideas, was.a sore subject for both. The mechanical powers represented in the plates, the Japanese said, were long since well known to them, but one of the prints explanatory of the refraction of rays, was a puzzle beyond solution. The anecdote attached to this plate is ludicrous and character. istic; they asked what it meant, and whether it did not relate to the distance between the sun and the earth? Captain G. thought it would be difficult to make Alexei comprehend this figure, and asked him whether he had not observed that, when the end of an oar was in the water, it had the appearance of being broken. O yes,' he said, "I have observed that, though I do not know how it happens." When we tried," says the Captain," to explain to him the refraction of rays, he asked us what a ray was? No sooner had we made him understand the meaning of the word, than he burst into a loud fit of laughter. "Oh, that's impossible!' said he, what man can break a ray?' We were likewise unable to repress our laughter, and the Japanese joined us without knowing erby."

important advantages, such, for example, that it is comparatively of small weight, and readily transferable from place to place, and that it can be made to act in any required direction; and is, in many cases, applicable when we should find it difficult to apply any other mechanical power. But it must be acknowledged, that its disadvantages also are considerable, arising principally from the friction, which is in some cases very great, and from the rigidity of the ropes with which the pullies are necessarily connected. Several ingenious contrivances have been de vised for removing, in a great degree, these and other inconveniences; of which the merit of one of the most important is due to Mr. White, who obtained a patent for his invention, of which he gives the following description:

The machine is exhibited in the above figure, and consists of two pullies Q and R; one fixed and the other moveable. Each has six

concentric grooves capable of having a cord passed round them, and thus acting like as many different pullies, having diameters equal to those of the grooves. Now, if we suppose each of these grooves to be a distinct pulley, and that all their diameters were equal, it is evident, that if any weight, for instance 144 lbs., were to be raised by pulling at S till the pullies touched each other the first pulley must receive th length of the string as many times as there are parts of the string hanging between it and the lower pulley.

In the present case there are twelve strings, b, d, f, &c. between the two principal pullies, formed by the passing of the cord over the six lower, and six upper grooves; whence, as much line must pass over the uppermost pulley, as is equal to twelve times the distance of the two. But from an inspection of the figure, it is obvious the second pulley cannot receive the full quantity of cord, by as much as is equal to the distance between

it and the first. In like manner, the third pulley receives less cord than the first, by as much as is the distance between the first and third; and so on to the last, which receives only one twelfth of the whole for this receives its portion of the line or cord n, from a fixed point in the upper frame from which it gains nothing; while all the others in the frame receive the line partly by turning to meet. it, and partly by its meeting them. Supposing now these pulleys to te equal in size and to move freely as the lines determine them; then it will be evident, from the nature of the system, that the number of their revolutions, and consequently their velocities, must be in proportion to the number of suspending parts that are between the fixed points above mentioned, and each pulley respectively. Thus the outermost pulley would go twelve times round in the time that the pulley, under which the part n of the line, if equal to it, would revolve once; and the intermediate times and velocities, would be a series of arithmetical proportionals, of which, if the first were one, the last would always be equal to the whole number of terms.

Since then, the revolutions of equal and distinct pullies are measured by their velocities, and that it is possible to find any proportion of velocity on a single body running on a centre; viz. by finding proportional distances from that centre; it follows, that if the diameters of certain grooves in the same substance be exactly adapted to the above series (the line itself being supposed inextensible, and of no sensible magnitude), the necessity of using several pullies in one frame will be obviated, and with that some of the inconveniences to which the pulley is liable.

THE DEFLAGRATOR OR DIAMOND MAKING MACHINE.

It has now been known a consi derable time, that water can be che mically decomposed into two gases oxygen and hydrogen, or different sorts of air; and that these two gases, if mixed in the same proportion in which they exist in the state of water and set on tire, give out a most intense heat. Advantage has been taken of this fact to construct an instrument by means of which small bodies can be subjected to a more violent heat than it is possible otherwise to produce. The principle on which it is made is very simple, and is the same as that of the common blow-pipe used by braziers and silversmiths, to fuze and unite separate pieces of metal. A large quantity of air is forced out as in this latter instrument, through a tube at a small opening at the end. The gases however cannot be breathed like common air, and an additional apparatus is necessary to contain, and force them out at a small hole, whics in the common blow-pipe is done by the lungs. A Dr. Hare, professor of chemistry in the University of Pennsylvania, was the first person we be lieve, who thought of applying these gases in the way of a blow-pipe, for the purpose of producing a great degree of heat. He inclosed each gas in a separate vessel, and caused them to mix in the requisite proportions to form water only at the moment of their exit and combustion. this means all danger of the gases exploding, which they will do if mixed and a spark comes into contact with them, was avoided. It is also necessary to keep the gases constantly compressed; for if any ces sation of the force were to take placų,

By

the gases being mixed explosion would also be caused. At the same. time, as they possess a great power of expansion, a considerable compressing force is necessary to retain them; and metallic vessels called gasometers have been expressly constructed to hold them, and constantly propel them out at cocks placed at at the bottom of the vessel to allow them to escape, or be retained at pleasure. Professor Hare, we believe, employed two of these gaso. meters; each possessing a compressing power equal to that of the other, calculated with respect to the different degrees of expansive power possessed by the two gases. The stream of air from each met at the moment of both reaching the common atmosphere, and being then set on fire, and directed on small bodies laid on charcoal, consumed vitrified or fused them. From 1802 to 1812, Dr. Hare and Professor Silliman made various experiments with this machine, and succeeded in fusing by it magnesia, lime, and various other earths, dissipating platina and other metals, and decomposing several substances, such as potass which had before obdurately resisted the most powerful agents. The effect of heat being, it is supposed, much increased, as far as decomposition is concerned, by the presence of pure hydrogen, which having a strong affinity for oxygen, attracts it from the substance submitted to the action of the " gaseous flame." From 1816 to 1819, Dr. Clarke, of Cambridge, also made a number of experiments with a gas blow-pipe; but his instrument differed from that of Professor Hare, by his employing only one gasometer, and mixing in it the two gases in the proper proportions. Although perhaps his method is neither so safe, nor so powerful, as that of Professor Hare, he succeeded by his brilliant experiments in attracting public atten. tion to the instrument, which though equally successful in America, had not before obtained much notice. He melted zircon, and ruby, converted several earths to metals, set fire to gold, and burnt platina like lead. Ever since the blow-pipe with these

gases has been looked on as a necessary instrument for every experimenting chemist, and its use has been frequently followed by brilliant and even astonishing results. They have all, however, been surpassed by the late success of Dr. Silliman. The American Journal of Science states, that this gentleman has succeeded, by means of this instrument in fusing. anthracite and plumbago (or black lead) and has actually converted them into diamonds. One of the most astonishing results of modern chemistry-previously known-is the fact that diamonds, plumbago, and charcoal are, chemically speaking, the same substance, with some very trifling differences, and under some modifications. Diamonds have been burnt, and have given the same results as charcoal, or plumbago when burnt; but hitherto it has not been found possible to make charcoal or plumbago assume the form of dia. monds. This is now effected by Professor Silliman. The following account of the results of his experiments has been published in the American papers. Plumbago appears to have been the matter experimented on; it was laid on the charcoal mentioned, which was employed to assist the fusion by its combustion:

"On the end of the prepared charcoal, and occupying an area of a quarter of an inch or more in dia meter, were found numerous globules of perfectly melted matter, entirely spherical in their form, having a high vitreous lustre and a great degree of beauty. Some of them, and generally they were those remote from the focus, were of a jet black, like the most perfect obsidian; others were brown, yellow, and topaz coloured; others were greyish white, like pearl stones, with the translucence and lustre of porcelain; and others limpid like flint glass, or in some cases like hyalite or precious opal, but without the iridescence of the latter.

"I detached some of the globules, and firmly bedding them in a handle of wood, tried their hardness and firmness; they bore strong pressure without breaking, and easily scratched not only flint glass but window glass,

and even the hard green variety, which forms the aquafortis bottles.The globules which had acquired this extraordinary hardness were formed from plumbago, which was so soft that it was perfectly free from resistance when crushed between thumb and finger." Some of the globules obtained in another experiment, were perfectly limpid, and could not be distinguished by the eye from portions of diamond." The experiments detailed remove every suspicion which might be entertained that these globules were the earthy matter contained in the plumbago, which was vitrified by the intense heat. They were exposed in a jar of oxygen gas to the focus of a powerful lens, and although they neither melted nor altered their forms, a decided precipitate took place on the introduction of lime water into the vessel. The globules of melted plumbago are as strictly non-conductors of electricity as the diamond." It will now probably not be deemed extravagant, if we conclude that this melted carbonaceous substance approximates very nearly to the condition of diamond."

Before we conclude, we must caution our readers not to suppose, that these results, though highly interesting and beautiful in a scientific point of view, will be of any great immediate advantage. Diamonds have very little intrinsic value, their use being almost confined to the purposes of ornament, and they are exchanged for so much money, merely because they are scarce. A means of making, or multiplying them at will, must therefore reduce their price, to the cost of manufacturing them. If more of them can be made, more persons will probably wear them as an ornament, and this will be the only immediate advantage which will accrue to mankind from the discovery. They are not like food, or clothing, or heat, essential to our existence and our welfare. Every improvement by which these can be produced, or the distribution of them regulated at a cheaper rate, tends to call more human beings into existence, and to increase the comfort and happiness of those who already exist.

INVENTED BY DR. HARE.

In the ordinary construction of the blowpipe by alcohol the inflammation is kept up by passing a jet, of alcoholic steam through the flame of a lamp, supported, as i usual, by a wick-otherwise the in flammation of the vapour does not proceed with sufficient rapidity to prevent the inflamed portion from being carried too far from the orifice of the pipe; and being so much cooled by an admixture of air, as to be extinguishe. By using two jets of vapour, in opposition to each other, Dr. Hare finds the inflammation may be sustained without a lamp, If one part of oil of turpentine, with