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The spines in the back fin and tail of some fishes are used in some parts of the world for pointing arrows. The serrated teeth of sharks are also used as offensive weapons. Fish-hooks are made of bone by some nations; and bones of fine texture, especially the teeth or tusks of the hippopotamus, elephant, walrus, and narwhal, are well adapted for carving, sculpturing, and turning. Ivory is also used for inlaying. Common bone furnishes excellent handles for small brushes, and other articles. In making utensils of bone, the compact cylindrical ones are preferred, as being stronger, and admitting of a more uniform and higher polish. The scrapings, shavings, or saw-dust of bone feteh a good price in the market, as they are much used by pastry-cooks and others as a material for jelly, which they readily give out to boiling water. Bone shavings arc also used in casehardening small articles of steel.

Bones also form a valuable manure, and for this purpose a supply is often obtained from many of our limestones, which contain abundant remains of corals and other animals. In the Saurian remains that abound in lias limestone there is a large store of phosphate of lime, and many of the corallines contain as much of this valuable substance as the bones of mammalia. A large proportion of the bones collected in London are conveyed to different parts of the country, to be used as manure. The sloops and cutters from Hull take in their cargoes of bones above London Bridge. These are stowed in the hold in a more or less putrid state: here they ferment, and diffuse a putrid odour to a great distance; and when the cargo is discharged at Hull, they are frequently reeking and smoking from decomposition. This probably softens them, and allows them to be more easily crushed at the mill. Bones are also imported into Great Britain from South America and other parts, and some of the most celebrated battle-fields of our own time are also said to have furnished considerable supplies of this valuable commodity.

Professor Johnston remarks that, while l00lbs. of bone-dust add to the soil as much organic matter as 33 lbs. of horn, or as 300 or 400 lbs. of blood or flesh, they add at the same time two-thirds of their weight of inorganic matter, consisting of lime, magnesia, soda, common salt, and phosphoric acid (in the phosphates), all of which must be present in a fertile soil, since the plants require a certain supply of them all at every period of their growth. These substances, like the inorganic matter of plants, may remain in the soil, and may exert a beneficial action upon vegetation after all the organic or gelatinous matter has decayed or disappeared. In order to bring the bones into a state in which the substances contained in them can be more readily taken up by the roots of plants, and at the same time be more uniformly distributed through the soil, the bone-dust is mixed with one-half its weight, and sometimes with its own weight, of sulphuric acid, diluted with from one to three times its bulk of water. After two or three days, with occasional stirring, the bones arc entirely dissolved or reduced. The solution or paste may be

dried up with charcoal-powder, with dried or charred peat, with sawdust, or with fine vegetable soil, and applied with the hand or with the drill to the turnipcrop; or it may be diluted with fifty times its bulk of water, and let off into the drills with a water-cart. This stimulates the young plants, and causes them to pass quickly through the first stage into the rough leaf, and thus they in great measure avoid the attacks of the fly and other insects, by which the tender plants of tardy growth arc often entirely cut off.

In some parts of the world bone is used as a fuel. In the treeless steppes of Tartary, and in the pampas of South America, it is considered that the bones of an ox will produce heat enough for the cooking of its flesh.

Many poor people in London gain a precarious livelihood by collectuig fragments of bone in the streets, which they sell to the manufacturers of salammoniac. The dealers in marine stores also purchase bones, which they dispose of in a similar manner, or to the soap-boilers. The bones thus collected are thrown into a cauldron of water, and boiled, for the purpose of clearing them of their fat, which is collected from the surface of the water, and used in the composrt ion of soap.

The bones arc then thrown into large retorts, and subjected to destructive distillation, the matter of the bone being resolved into its constituent elements from which new compounds are formed. Some of these pass off in vapour or gas, but the fixed principles remain in the retort. The volatile portions arc carbonic acid and various combinations of hydrogen and carbon, forming different kinds of inflammable air, together with water, holding carbonate of ammonia in solution, and a peculiar oil, which is collected and afterwards employed to feed the lamps burning in small close chambers, the sides of which thus become covered with Lamp-black. Towards the conclusion of the process, muriate of ammonia and sulphate of soda are formed: the latter is separated by dissolving in water and crystallizing, and the former (which is the sal-ammoniac, the great object of the manufacture) is obtained by sublimation.

The mass remaining in the retorts consists of the earthy and saline portions of the bone, blackened by the carbon of the animal matter, in which state it is called ivory black, boric black, and animal charcoal. This substance has a remarkable attraction for organic colouring matter, and is largely used for removing the colouring matter from syrup in the refming of sugar, and in the purification of many other organic liquors. By exposing ivory black to an open fire, the carbon is driven off, and the bones arc nearly blanched. These arc reduced to powder, which is used for making the cupels of the assayer [See Assaying], also as a polishing powder for plate and other articles, and also by the manufacturers of phosphorus for making lueifer matehes.

In the above process the inflammable gas might be collected, purified, and used for gas-lighting, in which case the only product thrown away would be the carbonic acid.

BOOKBINDING. The demand for books at the present period of our history, so greatly exceeding that of any former time, has had the effect of bringing together trades which before were scattered, and of supplying by machinery that which was formerly accomplished by manual skill and dexterity. This is the usual effect of a greatly increased demand, the conversion of trades and individual occupations into manufactures, and although the production of a book handsomely bound in cloth, with a figured or embossed cover, and gilt ornaments, and lettering, would seem to depend for its production more upon individual skill than upon large and complicated machinery, yet here, as in so many other cases, the manufacturer has, to a great extent, superseded the mechanic.

Nearly all the trades subsidiary to the production of a book have passed through similar mutations. The paper on which it is printed is no longer made by the slow and costly process of moulding or framing a sheet at a time, but is produced with wonderful rapidity by means of higldy complex and ingenious machinery: the ink with which it is printed is made in vast quantities in factories specially devoted to that sole object: the boards which form its sides are a distinct object of manufacture; the cloth which covers it brings into play textile machinery, the most elaborate in the world: the printing press which works off the copies is specially adapted to the steam engine, which sets it in motion with admirable speed and precision. Had it not been for changes such as these, which belong almost to our own day, the thirst for knowledge, which now happily pervades all classes, could never have been allayed; education could not have diffused her blessings, and the best security for national peace and order would have been wanting. In all these cases, the machimry which has superseded hand labour in some directions has led to a vastly increased amount of hand labour and intelligence in other directions. There is now a greater demand than ever for type-founders and for compositors, for literary men and for artists; for engravers on wood and engravers on metal. And if in the binding of a book, the workshop has expanded into the factory, and if many of the manipulations of the binder are now superseded by machines, there are more folders, more sewers, nay, there are even more finishers than formerly existed; for the great demand for machine-bound books, so to speak, has led to a corresponding increase in the better descriptions of binding, which depend almost entirely on the taste and skill of the workman. The same principle is at work throughout the useful arts. A successful machine may supersede certain descriptions of hand labour, and cause for a time much privation and suffering, but it is sure to increase the demand for labour in other branches; a well ascertained fact which ought to be constantly borne in mind by the intelligent workman. He ought to seek every opportunity of acquiring skill in more than one department of his trade, so that should his services in one direction be superseded by a machine, he may be able to apply his skill in another.

The effect of machinery upon the literary man has been, and is, in many respects highly beneficial. It is gradually raising his occupation into a profession, entailing the necessity of solid acquirements, an accurate style and business-like habits. He no longer writes under the uncertain favour of a patron, whose smiles must be purehased by the sacrifice of independence: he has now no occasion to dress like a man of fashion, or take charity in the shape of a humiliating "list of subscribers" to his work. The public is his patron, and his publisher his best friend.

Machinery has also had a marked effect in raising compositors into a highly intelligent and respectable class. It has increased their numbers and improved their efforts. Men who are constantly engaged in perpetuating information and intelligence must to a great extent become informed and intelligent. The compositor, the reader or corrector of the press, must be constantly assimilating some, at least, of the intellectual food which they assist in preparing for the world. Their labour can never be superseded by machinery, although machincry may greatly increase its extent and importance, and just in proportion as they become skilful and intelligent do they become valuable to the literary man with whom they are so intimately connected.

When the author and the compositor have accomplished their respective duties, the one in supplying "copy," and the other in "setting it up" in type, the manufacturing processes of a book may be said to begin. For the sake of convenience and economy, books are printed in sheets, the sizes of which are named according to the number and size of the pages in each sheet. The largest size is termed folio, (Latin folium, a leaf or sheet of paper;) the next size is quarto; then follow octaeo or 8vo; duodecimo or 12mo, 16mo, 18mo, 24mo, 32mo, &c., which contain on one form or side of the sheet 2, i, 8, 12, 16, 18, 24 and 32 pages respectively; but as all the sheets are perfected, that is, printed on both sides, these numbers must be doubled to give the actual number of pages in each sheet. Each of these sizes also admits of many varieties: thus, an octavo, although always consisting of 16 pages, may be square octaeo, royal octaeo, super-royal octaeo, &c., which leads to very great complication.

The arrangement of the pages of one side of a sheet or of a form in their proper order, and the wedging them up in an iron frame called a chase, preparatory to their being printed, is called imposing a sheet, and as the sheet is to be printed on both sides, there are two forms to be imposed for every sheet, an inner and an outer form; the outer form containing the first page of the sheet or of the book, and all the other pages which, when the sheet is folded, fall in their proper order with the inner form, which contains the second or left-hand page of the sheet, and all the other pages which, when the sheet has been folded and cut open, fall also m their proper order. The following diagrams will serve to illustrate some of the most important sizes of sheets,

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and the order in which the pages must be arranged in imposing the two forms of each sheet. It will be seen that by examining the folios or numbers of the pages of every two adjoining pages in a quarter, their sum makes one more than the number of pages in the whole sheet: thus in a folio 1+4 = 5 are imposed together; in a quarto 1 + 8 = 9; in an octavo 1 + 16 = 17; in a duodecimo 1 + 24; in sixteens 1 + 32, in eighteens 1 + 36, and so ou in every other size; this combination continues through all the other adjoining pages, according to the order in which they lie in the chase to be printed.

As a complete book or volume consists of a number of sheets, properly folded and following each other in the order of the folios or pages, it is necessary to have some distinguishing mark to each sheet for the convenience of the printer, the folder, and the binder. The numbers of the pages would be too slow and tedious for the purpose; their chief use being for the sake of convenient reference on the part of the reader. The printer, therefore, inserts at the bottom of the first page of every sheet, what he calls the sit/nature of the sheet,1 and this usually consists of the letters of the alphabet, the first sheet being usually marked B, (a being reserved for the title, contents, &c., which are usually printed last,) the second sheet is marked c, and so on throughout the letters of the old Roman alphabet, which did not contain the letters Jv and w: these arc therefore omitted. When this alphabet is exhausted, the twenty-third sheet is signed Aa or 2a, the twenty-fourth Bb or 2 B, and so on to the end. The third alphabet is written Aaa or 3 A, and so on. It is also used for the purpose of guiding the printer in imposing and the folder in folding, to insert other minor signatures at the bottom of the third page of every sheet. Thus, if the signature of the first page of an octavo sheet be B, the signature at the bottom of the third page of the same sheet is B2, and in some cases the fifth and seventh pages are marked respectively, B3, B4. In some cases, especially in books printed in France and Germany, numbers instead of letters are used for the signatures. If the work be in two or more volumes, the number of the volume is added to each sheet, thus, Vol. Ii. B would be the signature of the first sheet of the second volume. In foreign books this signature would be simply n 1. In both cases the number of the volume is inserted at the left hand bottom corner, and the letter or numeral near the right hand bottom corner.

In imposing a sheet of twelves or duodecimo, eight pages in each form are arranged together in the manner of a small octavo sheet. Above these eight pages, with a wider space between, four pages are ar

(1) This is sometimes improperly called the catch-trord. The catch-word is the first word of every page after the first, inserted at ti:e rigl.t-hand bottom corner of the preceding page, for the purpose as it was supposed of assisting a person in reading aloud, and insuring the correct turning over i! the pages. It is seldom used in modern printing.

ranged in each form, forming what is called the offeut. Iu folding the sheet, these four pages are first cut off, and the remaining eight folded like a sheet of octavo. The offcut is then folded down the middle twice, and inserted within the fold of the sixteen pages, thus forming altogether the required number twenty-four. In a sheet of this kind the signatures are carried to B 6, B 5 being the first page of the offcut, and however numerous the pages may be in a sheet with one signature, if they are all inserted, they are continued to the last odd page before the middle of the sheet, but they are never carried beyond the middle. In strictness it is not necessary to insert more than the first two to indicate the first fold of the paper, and the first of the offcut. The others only disfigure the pages, and are not of much use to the folder, who has only to keep the signatures on the outside, and the pages must "be folded correctly. In French books the first page of the offcut is often indicated by some small mark printed at the bottom, such as . .

No. 4 of the diagrams p. 153 is a sheet of twelves imposed with the first signature of the offcut in the inner form. By this arrangement it rises more conveniently for the folder, as it saves her the trouble of turning the offcut over every sheet. No. 5 is a sheet of sixteens to fold witnout cutting.

The sheets are delivered by the printer to the binder2 in one of two arrangements. Suppose an edition of 1,000 copies of an 8vo work is to bound; the printer either delivers at once 1,000 copies of signature A, 1,000 of B, and so on to the end, or he causes them to be previously gathered into quires; that is, a single sheet of z, supposing that to be the last sheet in the book, is taken, and upon this is placed a single sheet of Y; on this is placed a single sheet of x, and by proceeding in this way in a retrograde order, the gatherer at length arrives at B, the sheets being all in the proper order for folding. He then takes the title, contents &c., (signature A) and folding all the sheets together into a quire, lays them aside and proceeds to make up or gather a second quire, and so on till the whole 1,000 copies have been gathered.

The folding is performed at the binder's by females educated for the purpose. They are seated before a long flat board or bench, and each folder, placing the open quire of sheets before her, and with a foldingstick or paper-knife in her hand, folds the sheet in such a way that one page shall be exactly opposite to another in each sheet, taking care that the signatures shall fall properly. The folding is accomplished with remarkable precision and despatch, the result of long practice. A good folder will fold 500 octavo sheets per hour, but the usual average is about 300. In folding twelves with an offcut, the time occupied in folding is usually doubled.

(2) In preparing this notice of bookbinding, the Editor wishes to express his obligations to Messrs. Remnant, Edmonds & Remnant, of Lovell's Court, Paternoster Row, for allowing theit processes and machinery to be inspected and copied. In this large anil well-ordered establishment, 30,000 volumes per week are frequently done up in cloth, or bound in leather.

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printed, care must be taken not to allow it to set off, as the fresh ink has a tendency to make an impression on the opposite page, as was generally the case with new books when compressed by the old method, which was to beat them on a large smooth stone with a cast-iron bell-shaped hammer weighing 12 or 14lbs. This required some skill so as to compress or condense the sheets without marking them with the edge of the hammer, and to give the paper a smooth polished surface. This process was very much improved some years ago by Mr. Burn of Hatton Garden, who contrived a rolling press, Fig. 166, consisting of two iron cylinders, mounted and set in the

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passed through the rollers. This method not only renders the paper smoother than by hammer-beating, but the compression of the book is £th greater, a very desirable object, inasmuch as the book-shelves will contain nearly £th more books. These superior effects are also produced by the rollers in ^jth of the time required by the hammer. This method is now adopted for books that have been printed some time, in which the ink is properly set, and also for books that require re-binding.

After pressing, rolling, or hammering, each book is collated, to see that all the signatures run properly, and the plates (if any) are inserted in their proper places. The waste leaves are added at the beginning and end; the back and head are then knocked up square, and one side of the book is placed on a pressing board of the size of the book itself, and another similar board is laid on the upper side of the book, taking care to let the back of the sheets project about half an inch between the two boards. The workman then grasps the boards firmly between the thumb and fingers of the left hand, and lowers them into the cutting-press, Fig. 167, which consists of two strong wooden checks c c connected by two slide bars b b, and two wooden screws a s. The use of the two guides on one of the checks will be

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usual way at any required distance apart. A number of sheets, varying from 6 to 14, according to the size, being placed between two tinned iron plates, are

Fig. 167

explained hereafter, but it may be remarked that when these guides are not wanted, the press is turned completely over, so that these guides may be at the bottom, and out of the way. When the sheets are lowered between the cheeks c e, the press is screwed up tight by working an iron bar in the heads of the screws. The man then passes a tenon saw across the back of the sheets, so as to make a number of grooves, according to the size of the book, for the reception of the cords or bands for holding the threads in the sewing, and also for securing the boards which are to form the side covers. The number of bands depends upon the style of binding or method of finishing the book; periodicals, such as the Quarterly or Edinburgh Review, and boarded books, or books bound in cloth, have only two bands. But in the better descriptions of binding, 32mos sometimes have three bands; 18mo, 12mo, 8vo, and two-leaf 4tos, have 4 bands; royal octavo and whole sheet 4tos, 5 bands, and folios from 5 to 7 bands. In addition to these grooves for the bands, a groove is also formed at each end for the catch or keltic stitch. Supposing a book with two bauds is to be sewed, it is taken to the sewing-press, Fig. 168,' which is a

(I] This press is arranged for three bands, but for the sake of simplicity the description refers to two bands.

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