HABRAGE ON MACHINERY AND MANUFACTURES.

THIS work is the philosophy of tools; and it is the philosophy which teaches by example. The Economy of illaitqlitcr-ures is,., in fact, the theory of machinery as applied to the arts, illustrated. by a description of the internal arrangements of British maim-- factories.

Cambridge, though not celebrated for the practical mode in which:. it encourages the study of science, has given birth to two treatises.; on philosophy, preeminent for the genius with which principles have. been developed in works apparently occupied chiefly in the exposi- tion of facts. This treatise on the Economy of Manufactures, is to the • mechanical arts that which Mr. HERSCHEL'S Volume in Dr. Lard- ner's Cyclopeedia was to natural philosophy. Greater praise can scarcely be given to any philosophical writer, than to be classed with Haascnan : and in his work on the Study of Natural Philo- sophy, he excelled himself ; for there, principles, only to be reached, by minds of the highest order, were expounded with a lucidity and,. simplicity as beautiful as it was intelligible ; and philosophy was so adroitly mixed up with filet, that the reader's mind became illu- minated with both the theory of science and its application almost unconsciously, while he seemed to be passing through a book of - entertaining knowledge. A similar character may be given of Mr. BABBAGE'S work ; with this difference, that in the minds of many, the direct utility of arts and manufactures, and their iname-e diatc connexion with wealth and the comforts of life, may give Mr. BARRAGE'S work an advantage over one entirely occupied with the study and development of natural processes.

Such is the general character of this volume; but we must do more than convey our general impression. An analysis would be - difficult, and a few isolated specimens would be unsatisfactory. We are driven to the humble mode of enumerating the principal heads of the work, and referring to such matters under each as • may be most remarkable.

The work opens with a discussion of the sources of the advan- tages arising from machinery and manufactures. The advantages arising from machinery and manufactures may be thus analyzed,— the addition which they make to human power; the economy they produce of human time; the conversion of substances, apparently common and worthless, into valuable products. As an illustration • of the first of these advantages, produced by machinery, we will ' quote an experiment, simple enough in its nature, but the consi- deration of which may give the person unaccustomed to such re- flections some new ideas.

A block of squared stone was taken for the subject of experiment

1. Weight of stone 1080 2. In order to drag this stone along the floor of the quarry, roughly chiselled, it required a force equal to 758 3. The same stone dragged over a floor of planks required 652 4. The same stone placed on a platform of wood, and dragged over

a floor of planks, required

5. After soaping the two surfaces of wood which slid over each other, it required 182 6. The same stone was now placed upon rollers of three inches di- ameter, when it required to put it in motion along the floor of the quarry 34 7. To drag it by these rollers over a wooden floor 28 8. When the stone was mounted on a woollen platform, and the same rollers placed between that and a plank floor, it required 22

From this experiment it results that the force necessary to move a stone along the roughly-chiselled floor results, quarry is nearly two-thirds of its weight ; -to move haling a wooden flour, three-ilfths ; by wood upon wood, five-ninths; if the woeden surfaces are soaped, cue-sixth ; if rollers are used on the floor of the quarry, it requires one thirty-second part of the weight ; if they roll over wood, one-fortieth' and if they roll between wood, one-fiftieth of its weight. At each increase of knowledge, as well as on the contrivance of every new tool, human labour becomes abridged. The man Arbo contrived rollers, invented a tool by which his power was quintupled. The workman who first suggested the employment of soap or grease, was immediately enabled to move, without ex- erting a greater effort, more than three times the weight he could before.

The objects of machinery are susceptible of division : they may be classed as, first, those which are employed to produce power; anti secondly, those which are intended merely to transmit force.. The observations on the machines intended toproduce power, show neon in his true position as respects nature : he avails himself of the operations of nature by a knowledge of her ways, but he creates nothing, and produces nothing—but an effect.

Of those maclines by which we produce power, it may be observed, that al- though they are to us immense acquisitions, yet in regard to two of the sources of this power—the force of wind and of water—we merely make use of bodies in a state of motion by nature ; we change the directions of their movement in • order to render them subservient to our purposes but we neither add to nor diminish the quantity of motion in existence. When we expose the sails of a windmill obliquely to the gale, we check the velocity of a small portion of the atmosphere, and convert its own rectilinear motion into one of rotation in the sails ; we thus change the direction of force, but we create no power. The sari* may be observed with regard to the sails of a vessel ; the quantity of motion given by them is precisely the same as that which is destroyed imthe atmo. • sphere. If we avail ourselves of a descending stream to turn a water-wheel, we are appropriating a power which nature may appear, at firstoight, to be uselessly - and irrecoverably wasting, but which, upon due examination, we shall find she' is ever repairing, by other processes. The fluid which is falling from a higher to a lower level, carries with it the velocity due to its revolution with the earth.. at a greater distance from its centre. It will therefore accelerate, although to au

lbs.

606

almost infinitesimal extent, the earth's daily rotation. The sum of all these incre- ments of velocity, arising from the descent of all.the falling waters on the earth's surface, would in time become perceptible, did not nature, by the process of evaporation, convey the waters back to their sources and thus again, by re- moving matter to a greater distance from the centre, destroy the velocity gene- rated by its previous approach. The force of vapour is another fertile source of moving power ; but even in this case it cannot be maintained that power is created. -Water is converted into elastic vapour by the combustion of fuel. The chemical changes which thus take place are constantly increasing the atmosphere by large quantities of carbonic acid and other gases noxious to animal life. The means by which na- ture decomposes or reconverts these elements into a solid form, are not suffici- ently known ; but if the end could be accomplished by mechanical force, it is almost certain that the power necessary to produce it would at least equal that which was generated by the original combustion. Man, therefore, does not create power ; but, availing himself of his knowledge of nature's mysteries, he applies his talents to diverting a small and limited portion of her energies to his own wants: and, whether he employs the regulated action of steam, or the more rapid and tremendous efforts of gunpowder, he is only producing on a small scale compositions and decompositions which nature is incessantly at work in reversing, for the restoration or that equilibrium which we cannot doubt is con- stantly maintained throughout even the remotest limits of our system. The operations of man participate in the character of their author—they are diminu- tive, but energetic during the short period of their existence ; whilst those of nature, acting over vast spaces, and unlimited by time, are ever pursuing their silent and resistless career. •

- The chapters on the accumulation and regulation of power, con- sist of descriptions of ingenious devices for these purposes,—such as the fly-wheel in the first case, and the governor of the steam- engine and the hopper which supplies fuel at regulated intervals.

• Another very beautiful contrivance for regulating the number of strokes made

by a steam-engine, is used in Cornwall i it s called the cataract, and depends on the time required to fill a vessel plunged in water, the opening of the valve through which the fluid is admitted being adjustable at the will of the engine-luau.

Under the head of increase and diminution of velocity, the fol- lowing illustration of. the results to be gained by an ingenious ap- plication Of the same force occurs— An instance of the saving of time by making the same motion of the arm exe- cete two operations instead of one, occurs in the simple art of making the tags of boat-laces : they are formed out of very thin tinned sheet-iron, and were for- merly cut out of long strips of that material into pieces of such a breadth that When bent round they just enclosed the lace. Two pieces of steel have recently been fixed to the side of the shears, by which each piece of tinned-iron as soon as it is cut is bent into a semi-cylindrical form. The additional power required for this operation is almost imperceptible ; and it is executed by the same mo- tion of the arm which produces the cut. The work is usually performed by Women and children; - and with the improved tool, more than three times the quantity of tags is produced in a given time.

The economy arising from velocity is exemplified in the con- trivance used by haberdashers in taking stock, by which ribbons :are measured on a wheel, and also by which cotton balls are wound. In turning from small instruments to the larger and more im- portant machines, the economy arising from the increase of velocity becomes more striking.

In converting cast into wrought iron, a mass of metal of about a hundred- Weight is heated almost to a white heat, and placed under a heavy hammer moved by water or steam power. This is raised by a projection on a revolving axis • and if the hammer derived its momentum only from the space through which it fell, it would require a considerably greater time to give a blow. But as it is important that the softened mass of red-hot iron should reeeive as many blows as possible before it cools, the form of the cam or projection on the ails is such, that the hammer, instead of being lifted to a small height, is thrown up with a jerk, and almost the instant after it strikes against a large beam, which :acts as a powerful spring, and drives it down on the iron with such velocity that by these means about double the number of strokes can be made in a given time. In the smaller tilt-hammers, this is carried still further : by striking the tail of the tilt-hammer forcibly against a small steel anvil, it rebounds with such velocity, that from three to five hundred strokes are made in a minute. in the manufacture of scythes, the length of the blade renders it necessary that the workman should move readily, so as to bring. every part on the anvil in quick succession. This is effected by placing hint in a seat suspended by ropes from the ceiling so that he is enabled, with little bodily exertion, by pressing his feet against the block which supports the anvil, to vary his distance to any required extent. In the Manufacture of anchor's, an art in u-hich this contri- vance is of still greater importance, it has only been recently applied.

One of the Most useful applications of machinery, is to extend the time of action of forces. The half minute which we daily -de- Vote to the winding up of our watches, is an exertion of force almost insensible; yet, by the aid of a few wheels, its effect is spread over the whole twenty-four hours. Another familiar illustration may be noticed in domestic furniture : the common jack, by which our meat is roasted, is a contrivance to enable the cook in a few minutes to exert a force which the machine retails out during the succeeding hour in turning the loaded spit. The illustrations of the saving of time in natural operations, are only in part mechanical. Such is the shortening in the time of bleaching ; which is chiefly chemical. Not so, however, in tan- ning; that is purely mechanical, and very striking.

The object of this art is to combine a certain principle, called tanning, with every particle of the skin to be tanned. This in the ordinary process is accom- plished by allowing the skins to soak in pits containing a solution of tanning matter: they remain in the pits six, twelve, or eighteen months ; and in some instances (if the hides are very thick) they are exposed to the operation for two years, or even during a longer period. This length of time is apparently re- quired, in order to allow the tanning matter to penetrate into the interior of a thick hide. The improved process consists in placing the hides with the solu- tion of tan in close vessels, and then exhausting the air. The consequence of this is to withdraw any air which might he contained in the pores of the hides, and to employ the pressure of the atmosphere to aid capillary attraction in forc- ing the tan into the interior of the skins. The effect of the additional force thus brought into action can be equal only to one atmosphere, but a further improve- ment has been made : the vessel containing the hides is, after exhaustion, filled up with a solution of tan; a small additional quantity is- then injected With a forcing-pump. By these means any degree of pressure may be given which the containing vessel is capable of supporting ; and it has been found that, by em- ploying such a method, the thickest hides may be tanned in six weeks or two months. A very curious contrivance for measuring the quantity of fluid in gauging is mentioned, under the head of " Registering Ope rations.'

The time and labour consumed in gaoging tasks partly filled, has led to an improvement which, by the simplest means, obviates a considerable incon- veraence, and enables any person to read off, on a scale, the number of gallons contained in any vessel, as readily as he does the degree of heat indicated by his thermometer. A small stop-cock is inserted near the bottom of the cask, which it connects with a glass tube of narrow bore fixed to a scale on the side of the cask, and risinga little above its top. The plug of the cock may be turned into three positions : in the first, it cuts off all communication with the cask ; in the second, it opens a communication between the cask and the glass tube ; and, in the third, it cuts off the connexion between the cask and the tube, and opens a communication between the tube and any vessel held beneath the cock to receive its contents. The scale of the tube is graduated by opening the com- munication between the cask and tube and pouring into the cask a gallon of water. A line is then drawn on the scale opposite the place in the tube to which the water rises. This operation is repeated, and at each successive gal- lon a new line is drawn. Thus the scale being formed by actual measurement, both the proprietor and the excise officer see, on inspection, the contents of each cask, and the tedious process of gauging is altogether dispented with. Other advantages accrue from this simple contrivance, in the great economy of time whiCh.it introduces in making mixtures of different spirits, in taking stock, and in receiving spirit from the distiller.

The gas-meter is an instrument of this kind.

The " economy of materials employed " is shown in a contrivance of Mr. BRUNEL, by which very thin planks or veneers. are cut without any loss of wood. In ordinary sawing, of planks one inch thick, one eighth of the raw material is lost ; in veneers, perhaps one half ; and as veneers are cut from the most valuable wood, this saving is of importance.

' Another illustration arises out of the rapid improvements which have taken place in the printing-press during the last twenty years. • .

In the old method of inking type, by large hemispherical balls stuffed and covered with leather, the printer, after taking a small portion of ink from the ink-block, was continually rolling them in various directions against each other, in order that a thin layer of ink might be uniformly spread over their surface. This he again transferred to the type by a kind of rolling action. In such a i

process, even admitting considerable skill in the operator, t could not fail to happen that a large quantity of ink should get near the edges of the balls, which not being transferred to the type became hard and useless, and was taken off in the form of a thick black crust. Another inconvenience also arose,—the quantity of ink spread on the block not being regulated by measure, and the number and direction of the transits of the inking-balls over each other depend- ing on the will of the operator, and being irregular, it was impossible to place on the type a uniform layer of ink, of exactly the quantity sufficient for the im- pression. The introduction of cylindrical rollers of an elastic substance, formed by the mixture of glue and treacle, superseded the inking-balls, and produced considerable saving in the consumption of ink ; but the most perfect economy was only to be produced by mechanism. When printing-presses, moved by the power of steam, were introduced, the action of these rollers was found well adapted to the performance of the machine; and a reservoir of ink was formed, from which one roller regularly abstracted a small quantity at each impression. From three to five other rollers spread this portion uniformly over a slab (by most ingenious contrivances varied in almost each kind of press), and another travelling roller, having fed itself on the slab, passed and repassed over the type just before it gave the impression to the paper.

The " identity' of the work performed by machinery, is an im- portant advantage ; and the "accuracy," when the work is of differ ent kinds, is equally valuable. They are illustrated by numerous instances, in the course of Which occurs the following curious statement.

Of all the operations of mechanical art, that of turning is the most perfect. If two surfaces are worked against each other, whatever may have been their figure at the commencement, there exists a tendency in them both to become portions.of spheres. Either of them may become convex, and the other concave, with various degrees of curvature. A plane surface is the Enc of separation be- tween convexity and concavity, and is most difficult to hit; and it is more easy to make a good circle than to produce a straight line. A similar difficulty takes place in figuring specula for telescopes; the parabola is the surface which ..se- Orates the hyperbolic from the elliptic figure, and is the most difficult to form. If a spindle, not cylindrical at its end, is pressed into a hole not, Circular, and if the spindle lie kept constantly turning, there is a tendency in these two bodies so situated to become conical, or to have circular sections. If a triangu- lar pointed piece of iron be worked round in a circular hole, the edges Will gra- dually Wear, and it 'will become conical. These facts, if they do not explain, at least illustrate the principles on Avhich the excellence of work formed in the lathe depends.

The .chapter on " Copying " goes over a most important de- partment of the arts : the illustrations of each branch of the me- chanism of copying are too numerous to particularize. We can only recommend the whole, as well worth the attention of the reader. One invention under this head is too remarkable to be omitted.

'Printing sfront Copper-plates with altered Dimensions. —Some very singular specimens of an art of copying, not yet made public, were brought from Paris a few years since. A watchmaker in that city, of the name of Gonord, had contrived a method by which he could take from the same copper-plate im- pressions of different sizes, either larger or smaller than the original design Having procured four impressions of a parrot, surrounded by a circle, executed in this manner, I showed them to the late Mr. Lowry, an artist equally dis- tinguished by his skill, and for the many mechanical contrivanees with which he enriched his art. The relative dimensions of the several impressions were 5.5, 6.3, 8.4, 15-0, so that the largest was nearly three times the linear size of the smallest; and Mr. Lowry assured me, that he was unable to detect any lines in one which had not corresponding lines in the others. • There appeared to be a difference in the quantity of ink, but none in the traces of the engraving ; and from the general appearance, it was conjectured that the largest but one was the original impression from the copper-plate. The processes by which this singular operation was executed have not been published ; but two conjectures were formed at the time which merit notice. It was supposed that the artist was in possession of some method of transferring the ink from the lines of a copper- plate to the surface of some fluid, and of retransferrin.g the impression from the fluid to paper. If this could be accomplished, the print would be of exactly the same size as the copper from which it was derived ; but if the fluid were con- tained in a vessel having the form of an inverted cone, with a small aperture at the bottom, the liquid might be lowered or raised in the vessel by gradual ab- straction or addition through the apex of the cone ; in this case, the surface W which the printing-ink adhered would diminish or enlarge, and in this altered state the impression might be retransferred to paper. It must be admitted, that this conjectural explanation is liable to very considerable difficulties; for, al- though the converse operation of taking an impression from a liquid surface has a parallel in the art of marbling paper, the possibility of transferring the ink from the copper to the fluid requires to be proved. Another and more plausible

i explanation s founded on the elastic nature of the conipouncl of glue and treacle, a substance already in use in transferring engravings toearthenware. It is con- jectured, that an impression from the copper-plate is taken upon a large sheet of this composition ; that this sheet is then stretched in both directions, and that the ink thus expanded is transferred to paper. If lac copy is required to be smaller than the original, the elastic substance must first be stretched, and then receive the impression from the copperplate : on removing the tension it will contract, and thus reduce the size of the design. It is possible that one traus- fer may not in all cases suffice ; as the extensibility of the composition of glue and treacle, although eonsiderable, is still limited. Perhaps sheets of India rubber, of uniform texture and thickness, may be found to answer better than this composition; or passiblv the ink might be transferred from the copper-plate to the surface of a bottle of this gum, wha bottle might, after being expanded by forcing air into it, give up the enlarged impression to paper. As it would require considerable time to produce impressions in this manner, anti there might arise some difficulty in making them all of precisely the same size, the process might be rendered more certain and expeditious by performing that part of the operation which depends on the enlargement or diminution of the design only once; and instead of printing from the soft substance, transferring the design from it to stone : thus a considerable portion of the work would be reduced to an art already well known—that of lithography. This idea re- ceives some confirmation from the fact, that in another set of specimens, con- sisting of a map of St. Petersburg, of several sizes, a very short line, evidently an accidental defect, occurs in all the impressions of one particular size, but not in any of a different size.

The first section, or first half of the work, devoted to the me- chanical part of the subject, ends with a chapter of suggestions to those who propose visiting manufactories. It contains a series of questions, by the asking of which, the greatest quantity of information is likely to be obtained during the short space of time which can be spared from the avocations of a manufacturer for the purpose of gratifying the curiosity of the inquirer. The second section, on the domestic and political economy of manufactures, opens with the distinction between making and manufacturing.

There exists a considerable difference between the terms making and manu- facturing. The former refers to the production of a small, the latter to that of a very large number of individuals; and the difference is well illustrated in the evidence given before the Committee of the House of Commons on the Export of Tools and Machinery. On that occasion Mr. Maudslay stated, that he had been applied to by the Navy Board to make iron tanks for ships, and that he was rather unwilling to do so, as be considered it to be out of his line of business; however, he undertook to make one as a trial. The holes for the rivets were punclual by hand-punching with presses' and the 1,680 holes which each tank required cost seven shillings. The Navy Board, tvho required a large number, proposed that he should- supply forty tanks a week for many months. The magnitude of the order made it worth while to commence manufacturer, and to make tools for the express business. Mr. Maudslay therefore offered, if the Board would give him an order for two thousand tanks, to supply them at the rate of eighty per week. The order was given : he made tools, by which the expense or punching the rivet-holes of each tank was reduced from seven shillings to nine-pence - he supplied ninety-eight tanks a week for six months, and the price charged for each was reduced from seventeen pounds to fifteen.

"The influence of verification of price," presents some novel considerations. The cost of an article to the purchaser, is the price he pays for any article, added to the cost of verifying the fact of its having- that .degree of goodness for which he contracts. From among the numerous instances given of the cost arising from frauds, we select one.

There are few articles which the public are less able to judge of than the quality- of drugs; and when they are compounded into medicines, it is scarcely possible even for medical men, to decide whether pure or adulterated drugs have been emploYed. This circumstance, concurring with an injudicious mode adopted in the payment for medical assistance, has produced a curious effect on the price of medicines. Apothecaries, instead of being paid for their services and skill, have been remunerated by being allowed to place a high charge upon the medicines they administer, which are confessedly of very small pecuniary value. The tendency of such a system is to offer an inducement to prescribe more medicine than is necessary ; and in fact, even with the present charges, the apothecary, in ninety-nine cases out of a hundred, cannot be fairly remunerated unless the patient either takes or pays for more physic than is really necessary. The apparent extravagance of the charge of eighteen-pence for a two-ounce phial* of medicine, is obvious to many who do not reflect on the circumstance that the charge is, in reality, for the payment of professional skill. As the same charge is made by the apothecary, whether he attends the patient or merely prepares the prescription of a physician, the chemist and drug- gist soon offered to furnish the same commodity at a greatly diminished price. But the eighteen-pence charged by the apothecary might have been fairly divided into two parts —three:pence for medineand bottle, and fifteen-pence for

attendance. Now the o chemist, although he has reduced the price of the apothecary's draught from thirty-three to forty-four per cent., yet realizes a profit of between two and three hundred per cent. on the tenpenee or shilling which he charges for the same compound. This enormous profit has called into existence a multitude of competitors; and in this instance the impossibility of verifying has, in a petition. The great measure, counteracted the beneficial effects of com-

e general adulteration of drugs, even at the extremely high price at which they are retailed as medicine, enables those who are imagined to sell them man unadulterated state to make large profits, whilst the same evil frequently disappoints the expectation and defeats the skill of the most eminent physician. It is difficult to point out a remedy for this evil, without suggesting an almost total change in the system of medical practice. If the apothecary were to charge for his visits, and to reduce his medicines to one-fourth or one-fifth of their present price, he would still have an interest in procuring the best drugs for the sake of his own reputation or skill ; or if the medical attendant, who is paid more highly for his time, were to have several pupils, he might himself supply the medicines without a specific charge, and his pupils would derive improvement from compoundingthem, as well as from examining the purity of the drugs he would purchase. The public would derive several advantages • Apothecaries frequently purchase these phials at the old bottle-warehouses at .ten thillings per-gross; so that when their servant has washad'them, the cost of the phial is nearly one penny.

from this arrangement. In the first place, it would be greatly for the interest of the medical practitioner to have the hest drugs ; it would also be his interest not to give more physic than needful ; and it would also enable him, through some of his more advanced pupils, to watch more frequently the changes of any malady.

" Price as measured by Money," is a copious chapter, and enters upon considerations well worthy of the attention of all those in- terested in manufactures. The means of comparing prices at different epockS, are composed of various elements, which are here suggested : it is not enough to have a table of prices of Birming- ham, or any other goods, at stated periods.

The great diminution in price of the articles here enumerated may have arisen from several causes—I. The alteration in the value of the currency. 2. The increased value of gold, in consequence of the increased demand for coin. The first of these causes may have had some influence ; and the second may havehad a very small effect upon the two first quotations of prices, but none at all upon the two latter ones. :3. The diminished rate of profit produced by capital, however employed. This may be estimated by the average price of 3 per cents. at the periods stated. 4. The diminished price of the raw materials out of which these articles were manufactured. The raw material is principally brass and iron ; and the reduction upon it may, in some measure, be estimated by the diminished price of iron and brass wire, in the cost of which articles the labour bears a less proportion than it does in many of the others. 5. 7:he smaller quantity of raw material employed, and perhaps, in some instances, an inferior quality of workmanship. 6. The inqn °reel means by which the same effect was produced by dirnintshedlabour.

The " Division of Labour" is exemplified, as it was by ADAM SMITH, by the manufacture of pins ; with this novelty, that Mr. BABBAGE shows the economy of employing workmen or women of different grades of skill on the different parts of the work. He afterwards gives a description of a very curious machine, invented by an American, for making a pin with an immoveable head, by a machine, from the first process to the last ; andin which nothing is done by hand but the papering. The division of mental labour necessarily brings on the Lapis the calculating-machine, on which Mr. BABBAGE has been long occupied, and which will be the last and perhaps the highest example yet known of the apparent spontaneity of machinery. . In "the Copses and Consequences of Large Factories," occurs the interesting illustration of their utility in economizing both labour and the raw material.

Amongst the causes which tend to the cheap production of any article, and which require additional capital, may be mentioned, the 'care which is taken to

allow no part of the raw produce, out of which it is formed, to be absolutely wasted. An attention to this circumstance sometimes causes the union of two trades in one factory, which otherwise would naturally have been separated. An enumeration of the arts to which the horns of cattle are applicable, furnishes a striking example of this kind of economy. The tanner who has purchased the hides separatesthe horns, and sells them to the makers of combs and lanterns. The horn consists of two parts, an outward horny case =tan inward conical- shaped substance, somewhat intermediate between indurated hair and bone.. The first process consists in separating these two parts by means of a blow against a block of wood. The horny exterior is then cut into three portions by means of a frame-saw.

1. The lowest of these, next the root of the horn, after undergoing several processes, by which it is rendered fiat, is made into combs. 2. The middle of the horn, after being flattened by heat, and its transparency improved by oil, is split into thin layers, and forms a substitute for glass in lan- terns of the commonest kind.

3. The tip of the horn is used by the makers of knife-handles and of the tops of whips, and for other similar purposes. 4. The interior, or core of the horn, is boiled down in water. A large quan- tity of fat rises to the surface ; this is put aside, and sold to the makers of yellow soap: 5. The liquid itself is used as a kind of glue, and is purchased by the cloth- dressers for stiffening. 6. The bony substance which remains behind is then sent to the mill, and, being ground down, is sold to the farmers for manure.

Besides these various purposes to which the different parts of the horn are ap- plied, the clippings, which arise in comb-making, are sold to the farmer for ma- nure at about one shilling a bushel. In the first year after they are spread over the soil they have comparatively little effect, but during the next four or five their efficiency is considerable. The shavings which form the refuse of the lantern-maker, are of a much thinner texture : a few of them are cut into vari- ous figures and painted, and used as toys • for, being hygrometric they curl lip when placed in the palm of a warns hand. But the greater partof these shav- ings are sold also fur manure, which, front their extremely thin and divided form, produces its full effect upon the first crop.

It would be agreeable in this manner to follow Mr. BABBAGE chapter by chapter; but the temptation of transferring curious and useful remarks and examples from his pages to our columns, is great, and by yielding to it we should be protracting this article to a disproportionate length. The chapters on contriving machi- nery—on the proper circumstances for the application of machinery —on the duration of machinery—on its exportation, and on the effect of taxes on manufactures—are all especially useful and in- teresting; but this recommendation is all the notice we can at present bestow upon them. In some portions of the work, we regret to see that a less peaceful spirit animates Mr. BABBAGE than becomes a philosopher. The paragraph relating to the Presidency of the Royal Society by the Duke of SUSSEX, we consider illiberal and unjust. Preceding his Royal Highness's election, it would only have been erroneous; after it, it partakes of malignity—a determination to give pain where no good can be done. The consideration of Booksellers' Profits, is drawn in, after the manner of Hercules, by head and shoulders ; and we some- what suspect the motive. It involves, however, a question of great literary importance; and in another and fitter place, we shall probably discuss its merits. In the mean time, we may ob- serve, that Mr. BABBAGE has said a great deal of the gains of the bOokseller, but nothing of his losses.