PEACOCK'S METALLIC PISTON. Sir, I have lately made a full-sized drawing of a metallic piston invented by a working engineer, Mr. Alexander Peacock; by his permission I have reduced it to the size of your page, and beg to hand it to you with the accompanying description, with a view of giving the public the benefit of his invention, through the medium of your extensively circulated Magazine.

The merit of this piston consists in the simplicity of its construction, having but one spring, which from its form and position cannot fail of acting.

He considers it peculiarly adapted for engines subjected to uneven work, and particularly for horizontal cylinders, and therefore very applicable to locomotives.

Fig. 1 is a plan with the top lid or cover off. Fig. 2 a central section, and Fig. 3 an edge view; the same letters apply to the same parts in all the figures. o, the outer ring, is cut at c, and the tongue t is held in its place by the screw s, from the inner ring i; this inner ring is cut at a, on the opposite side. g is the elliptical, and only spring, put loose between the lower and upper covers; ll are two pairs of levers extending from the sides of the spring to the rings, one pair pressing immediately upon the outer, and the other upon the inner ring; these levers are connected at either end by a plain rule joint.

It will be readily seen that as the outer ring wears, the spring proportionally opens or extends, and pressing on the radial levers, and these against the ring, keeps it up to its work.

As it is material that a piston, particurlarly for a horizontal cylinder, should be always replaced in the same relative position to the cylinder, provision is made to ensure this by the screw b working in a slot cast upon the inner ring,

There is no necessity for occupying your columns by describing the other well-known parts of a piston, Several to whom I have shown it, agree in declaring this to be a good practical invention. I remain, Sir,

THE USEFUL ARTS IN CHINA.

The literary labours of Protestant Missionaries have added but little to our knowledge of the countries in which they have been stationed, or the manners of their inhabitants. Many of them, indeed, seem to have held it a point of conscience to deprive their journals-such, at least, has been the case with those which have seen the light-as much as possible of all interesting information on mere mundane affairs; so that we have been presented with accounts of a residence in Siberia, or a tour in India, which, for aught of "special matter' contained in them, might as well have been written within the purlieus of Camden Town or Chelsea. There are symptoms abroad, however, of a change in this particular, and our stock of geographical knowledge has been not a little increased during the last few years, by the publications of English and American Missionaries. Another work of this better kind has just been added to the list,* and not at all too soon, if our modern missionaries may be expected to contribute to our acquaintance with China and the Chinese in anything like an equal ratio with their Catholic predecessors, to whom the "barbarian" world is indebted for all the most valuable information it possesses with regard to the Celestial Empire.

The greater portion of Mr. Medhurst's volume is occupied with the details of his proceedings in his mission, and especially of the celebrated voyage to the north of China, in the course of which Mr. M. persisted in repeatedly landing, in defiance of the constituted authorities, and distributing to the astonished natives a plentiful assortment of religious tracts, in their own language. What good purpose was likely to be served by this irregular proceeding does not very plainly appear; certain it is, that, as might be expected, it effectually roused the attention of the Chinese government; and, it is equally certain, that not a single step towards a freer intercourse has ever been gained by any of the numerous attempts

* China, its State and Prospects, with special reference to the Spread of the Gospel; containing Allusions to the Antiquity, Extent, Population, Civilization, Situation, and Religion of the Chinese. By W. H. Medhurst, of the London Missionary Society. Illustrated with Engravings on Wood by George Baxter. London, 1838. Snow. 8vo., pp. 598.

which have been made from time to time to carry matters with a high hand, and, in a manner, coerce the Chinese into liberality. On the occasion in question, the government was evidently taken by surprise, as it well might be,-but we question whether, now that its vigilance has been roused, a similar voyage, with similar proceedings on landing, would be at all practicable. Wonderful progress has often been made, for a short time, in forcing an intercourse in opposition to the Chinese authorities,-but it has uniformly happened that, in the end, those authorities have carried every contested point, and placed the assailing party in its former, if not even in a retrograde position. There is little reason to doubt that such would also be the result of any attempt to renew the strange transactions commemorated in Mr. Medhurst's work. The experiment will, most probably, be soon tried, and then nous verrons!

The narrative portion is preceded by several chapters devoted to the other subjects mentioned in the title-page, and among the rest, when "civilization" comes to be considered, to the state of the arts and manufactures-the truest touchstone of a nation's real position in the social scale. The whole of this part of the volume abounds in interest, and a few pages, extracted at random, would be almost certain to give a favourable opi nion of our author's labours. Although, we are afraid, no inventions of equal importance to those of printing and gunpowder remain in the exclusive possession of the Chinese, some advantages might, nevertheless, accrue to the useful arts from a closer investigation than has ever hitherto been made into the processes which resemble in the main those of our western world, but which, from their having been necessarily perfected without any acquaintance with our corresponding methods, may very possibly present points of difference well worthy of notice and imitation, and at the same time not likely to be hit upon amongst those who have long looked on their own way as the way, and have, perhaps, from inveterate habit, never dreamt of the possibility of the existence of any other. In this manner the study of the longestablished industrial processes of the Chinese may be turned to account; but there can be no question that, if a 66 re

ciprocity system" were established tomorrow, the Chinese would have a thousand times more to borrow of the outer barbarians than the outer barbarians of the Chinese. The steam-engine alone would be a contribution from this side of the world which our tea-growing friends would find it rather difficult to balance, to say nothing of its endless applications to purposes of utility,—the printing-machine, for instance. This brings us to an interesting point. Notwithstanding all he has to say in its fayour, the Chinese process of printing, as described by Mr. Medhurst, presents a striking contrast to the speedier operations with which the use of moveable types, combined with the indefatigable labours of the steam-press, have made us familiar. We quote Mr. Medhurst's description, as well for this reason, as from its being a fair specimen of his style of handling the subject.

"The mode of printing adopted by the Chinese is of the simplest character. Without expensive machinery, or a complicated process, they manage to throw off clear impressions of their books, in an expeditious manner. Stereotype, or block printing, seems to have taken the precedence of moveable types in all countries, and in China they have scarcely yet got beyond the original method.

"The use of wooden blocks has not been without its advantages; among which we may enumerate speed and cheapness. The first part of the process is, to get the page written out in the square or printed form of the character. This having been examined and corrected, is transferred to the wood in the following manner :-The block, after having been smoothly planed, is spread over with a glutinous paste; when the paper is applied and frequently rubbed, till it becomes dry. The paper is then removed, (as much of it as can be got away,) and the writing is found adhering to the board, in an inverted form. The whole is now covered with oil, to make the letters appear more vivid and striking, and the engraver proceeds to his business. The first operation is, to cut straight down by the sides of the letters, from top to bottom, removing the vacant spaces between the lines, with the exception of the stops. The workman then engraves all the lines which run horizontally; then, the oblique; and, afterwards, the perpendicular ones, throughout the whole page which saves the trouble of turning the block round for every letter. Having cut round

the letters, he proceeds to the central parts ; and, after a while, the page is completed. A workman generally gets through one hundred characters a day, for which he will get sixpence. A page generally contains five hundred characters. When the engraver has completed his work, it is passed into the hands of the printer, who places it in the middle of a table; on one side is a pot of liquid ink, with a brush; and on the other a pile of paper: while, in front, there is a piece of wood, bound round with the fibrous parts of a species of palm, which is to serve for a rubber. The workman then inks his block with the brush: and taking a sheet of dry paper, with his left hand, he places it neatly on the block; and seizing the rubber with his right hand, he passes it once or twice quickly over the back of the paper, when the impression is produced, the printed sheet hastily removed, and the workman proceeds with the next impression, till the whole number is worked off; and thus, without screw, lever, wheel, or wedge, a Chinese printer will manage to throw off 3000 impression in a day. After the copies are struck off, the next business is to fold the pages exactly in the middle; to collate, adjust, stitch, cut, and sew them; for all of which work, including the printing, the labourer does not receive more than ninepence a thousand. The whole apparatus of a printer, in that country, consists of his graves, blocks, and brushes; these he may shoulder and travel with, from place to place, purchasing paper and lamp-black as he needs them; and, borrowing a table anywhere, he may throw off his editions by the hundred or the score, as he is able to dispose of them. Their paper is thin, but cheap; ten sheets of demy size, costing only one halfpenny. This, connected with the low price of labour, enables the Chinese to furnish books to each other for next to nothing. The works of Confucius, with the commentary of Choo-foo-tsze, comprising six volumes, and amounting to four hundred leaves, octavo, can be purchased for nine-pence; and the historical novel of the three kingdoms, amounting to 1500 leaves, in twenty volumes, can be had for half-a-crown. Of course, all these prices are what the natives charge to each other; for all which Europeans must expect to pay double.

"Thus books are multiplied, at a cheap rate, to an almost indefinite extent; and every peasant and pedlar has the common depositories of knowledge within his reach. It would not be hazarding too much to say, that in China there are more books, and more people to read them, than in any other country of the world."—p. 103.

66

Many of the praises here bestowed by Mr. Medhurst on the Chinese practice, must be taken with a very considerable allowance. We cannot very well see why the attribute of "speed" as well as cheapness" is to be ascribed to it. From his statement it would appear that a workman is occupied five days in producing a block for a single page of a common size. What sort of "speed" is this, compared to that attained by the use of single types? And by what miracle would the Chinese, with their

speedy" method, manage to get out such a sheet as the double Times, in the course of a few hours? The thing is clearly impossible; and Mr. Medhurst would therefore have done better to adduce rapidity as one recommendation of a process, which in its very nature must be slow. The "cheapness" is also rather problematical. True, the expense of engraving a page does not strike the English reader as any way alarming; but engravers are not to be had everywhere for sixpence a day. The process is only comparatively, not positively cheap,cheap not from its inherent simplicity, but merely on account of the cheapness of labour in China, from the overstocked state of the labour-market. Did the Chinese language admit of the introduction of moveable types, (which a former Emperor once attempted,) and were the Chinese acquainted with the art of typefounding, our system would be far cheaper than their own, it being recollected that where wood-engravers are to be had for sixpence a day, type-founders must be procurable at a proportionate To make the matter clear, let us only imagine the reverse to take place,— the introduction of the Chinese method into England. Supposing our artist to be as expert as his Eastern prototype, and to be satisfied with six shillings a day, (no very extravagant wages, it will be owned,) here are at once thirty shillings for the labour alone of "setting up" a single page-and that, too, a page only of the extent of one of our columns, reckoning every "character" to represent a word. This, indeed, is allowing nothing for the casting of the types, but this may be set against the value of the Chinaman's block, which, it should be borne in mind, will serve for only one page, while the more expensive type may

sum.

be distributed and set up again ad infinitum.

The mode of obtaining the impression is a different matter altogether; in this case something is likely to be gained from an observation of the Chinese fashion. Our ideas are so bound up with "the press," that it appears to us an essential of "the glorious art;" and we are so often in the habit of toasting "the Liberty of the Press," that is seems almost sacrilegious to compass and imagine the printing of a book without its aid. Yet the Chinese have printed for ages without having heard of "the Press" at all! The great simplicity of their process is a most striking feature, while even the limited experience which has been had of it in England, (where a similar method is adopted for taking engravers' proofs, &c.,) is sufficient to demonstrate that it is compatible with the highest degree of typographical excellence. Would it not be worth the while of some of our ingenious mechanics to turn their thoughts in this direction? Ingenuity has been lavishly bestowed on the improvement of the printing press, until the maximum of power in that engine may be presumed to be attained. Why not try invention on another tack, and apply English skill in machinery to the perfecting of a mode of printing on the Chinese plan, where the impression is obtained by gentle friction, instead of a tremendous direct impression? Could this be achieved, it would probably be one of its not least important results, that type might be made of a much less valuable material than at present, and by a much less expensive and elaborate method. At any rate the attempt is worth making,though it would probably be necessary to commence by introducing a much softer texture of paper than that now used, and, perhaps, to print, like the Chinese, on one side only.

Mr. Medhurst is again, towards the conclusion of our extract, rather too solicitous to exalt the cheapness of Chinese literature. The number of volumes to be had for a few pence may seem rather startling, but then he should have stated, that volumes of Chinese books are by no means of such substantial dimensions as our own. For instance, the six volumes of Confucius, it appears, contained altogether only four hundred leaves, (that is, four hundred pages, being printed on

one side only,) containing only about half as much as a common English volume of the octavo size. Nine-pence certainly seems low enough for this quantity of matter, but then this sum of ninepence in China, be it remembered, forms the whole earnings of an artist for a day and a half; so that, all things considered, it is evident that our own standard works are sold at a much lower rate than this much-vaunted and inconceivably cheap edition of the great Chinese classic. If books, therefore, are sold in China for "next to nothing," what are we to think of the price of such commodities at home? It would be as well for Mr. Medhurst to avoid such mystification for the future.

The present work, in all its mechanical details, is well got up. It is illustrated by several well-executed wood-cuts; the frontispiece especially, which represents the author seated opposite to a learned young Chinese, (who accompanied Mr. M. to England, and addressed a number of public meetings in his own language,) is remarkable both for the interest of the subject, and the excellent style in which it has been engraved and printed in colours by Mr. Baxter's patent process.

INDIAN STEAM NAVIGATION-REPLY TO MR. BAYLEY.

Sir, Mr. Bayley (page 262) seems so obstinately bent on taking the alarm at the intended progress of the Dutch in Indian steam navigation, that it would be useless to waste any more discussion on that subject, especially as Mr. B. is probably the only "constant reader" of the Mechanics' Magazine who remains in the same state of needless excitement, after the perusal of the facts admitted by that gentleman himself in his former letter. There are one or two things, however, in his last, which call imperiously for observation.

For one thing, Mr. Bayley intimates that no such vessel as a private steamer has been heard of in India. To convince him of the fact, nevertheless, recourse need only be had to the pages of a work of which he calls himself a constant reader," although, if he be so, he