sheets, and assists in keeping the upper and lower parts | binding. These are cut out separately, thinned at of the hollow back in shape, when the book is closed. the edges, and attached by means of glue. The The book, still in the rough boards, is fixed by one blind-tool ornaments of the book are put on by means corner in a small portable screw-press, as in Fig. 179, of pieces of brass, cut into the desired pattern and and a small strip of mill-board, placed on edge at the shape, and mounted in handles, as in Figs. 180, 181. back, is secured by passing a needle and thread two Fig. 180. Fig. 181. or three times between the leaves through the solid back, and over and under the small strip; the thread, which is generally of silk or cotton, two or three colours being sometimes used, is then twisted or plaited over the strip, and when about a third or one-half is covered, it is further secured by a few Fig. 179. stitches through the solid back. The plaiting or covering is then completed, and is secured as before by sewing through the back. The superfluous portions of the strip are then cut off. This description of head-band is called worked; a commoner description, called stuck-on, is a piece of striped or coloured linen, enclosing a piece of cord, stuck or glued to the back of the book. The bands or raised projections at the back of the book are formed by glueing strips of mill-board, leather, or cord across them. The book is now ready for covering. The leather may be calf, or morocco, or russia; but, whatever the leather, it is carefully chosen, so as to be free from blemishes, and of the proper size, and, being placed on a flat board, with the rough side up, the edges are pared thin with a sharp knife, so that in turning them over the board, they may not bulge out into unsightly projections. The leather is then damped, and covered with paste, and applied to the book, a few simple tools being used to smooth it down and press it into shape, to square the edges, and to raise the bands. The leather is neatly turned in at the top and bottom, and then folded over the head-bands. When the sides and edges are nicely smoothed and squared, the bands at the back are raised, and the spaces between them depressed, by working them with a bone paper-knife, and during all these manipulations the man every now and then moistens the leather with a bit of wet sponge. When the leather cover is properly arranged, the marbled or other lining papers are inserted, and the book is put into the standing press for a few hours, after which it is ready for tooling. But in some descriptions of binding, a good effect is produced by having distinct lettering pieces, of a different colour from the general VOL. I. If a long line, plain or figured, is to run up the sides of the book, it is cut upon the periphery of a disc of brass, Fig. 182, moving upon a central axis, and furnished with in this way he can roll the tool the whole length of each side of the cover. All these tools are heated at a gas-stove, Fig. 183, a great improvement on the unwholesome charcoal brazier formerly in use. The small tools are pressed down with an equable force in those parts of the cover where they are wanted. Gilt tooling is produced by covering the parts to be gilt first with glaire and then with gold leaf, and then pressing the hot tool upon the part thus covered. On wiping off the gold with a rag, that part of the gold only is attached which came in contact with the hot tool. Lettering is performed commonly by a set of lettering tools, each letter of the alphabet being cut out in brass, and mounted in a wooden handle. Letters, numerals, &c., are kept of different sizes; but for words in common use, such as "Holy Bible," 'Atlas," &c., tools are kept, with the whole word or words cut in them, as in Fig. 184. When the ornaments, lettering, &c., are complete, the book is finished off with polishing-irons, of various shapes and sizes, one of VAITA which is shown in Fig. 185. These are heated, and Fig. 185. Fig. 183. Fig. 184. passed over the leather, and also over the marble lining-paper, &c. We have thus gone over the principal processes concerned in binding a book. A few years ago, a. method of binding by means of caoutchouc cement was patented by Mr. Hancock, by which the operations of sawing-in, sewing, rounding, and the use of M gluc are dispensed with, and instead of leaves attached | in water a strip of mill-board about a quarter of an by thread stitches at two or three points, they are agglutinated securely along their whole length. This plan is admirably adapted for binding engravings, maps, manuscripts, and collections of letters, which have little or no margin left at the back for the stitch ing. The plan has been thus described:-" After folding the sheets in double leaves, the workman places them vertically, with the edges forming the back of the book downwards, in a concave mould, of such rounded or semi-cylindrical shape as the back of the book is intended to have. The mould for this purpose consists of two parallel upright boards, set apart upon a cradle frame, each having a portion or portions cut out vertically, somewhat deeper than the breadth of the book, but of a width nearly equal to its thickness before it is pressed. One of these upright boards may be slidden nearer to or further from its fellow, by means of a guide-bar, attached to the sole of the cradle. Thus the distance between the concave bed of the two vertical slots in which the book rests may be varied according to the length of the leaves. In all cases about one-fourth of the length of the book at each end projects beyond the board, so that one-half rests between the two boards. Two or three packthreads are now bound round the leaves thus arranged, from top to bottom of the page, in different lines, in order to preserve the form given to the back of the mould in which it lay. The book is next subjected to the action of the press. The back, which is left projecting very slightly in front, is then smeared carefully by the fingers with a solution of caoutchouc, whereby cach paper-edge receives a small portion of the cement. In a few hours it is sufficiently dry to take another coat of a somewhat stronger caoutchouc solution. In forty-eight hours four applications of the caoutchouc may be made and dried. The back and the adjoining part of the sides are next covered with the usual band or fillet of cloth, glued on with caoutchouc; after which the book is ready to have the boards attached, and to be covered with leather or parchment, as may be desired." Vellum binding is a distinct branch of the trade, and is applied to the binding of every description of account-book. The paper is first folded and counted into sections, which in foolscap generally consist of six sheets, and above that size, of four sheets. These are sewed upon strips of vellum, three strips being usually applied to foolscap folio, and a greater number for larger sizes. In sewing account-books, waxed thread is used as being stronger. After sewing, the first ruled leaf at each end is pasted to the waste paper and the marble lining paper inserted. The back is then glued, and when dry, the fore edge is cut and the back rounded, a rounder back and consequently a deeper hollow being given than in printed books. The two ends are then cut and the edges marbled. The head-bands are worked on a slip of mill-board as before described. Strong pieces of canvass or buckram are then glued at the top and bottom of the back and between each of the vellum slips. A hollow back is produced by soaking inch wider than the back of the book and gluing it on both sides; it is then placed on a sheet of paper, and a roller corresponding to the curvature of the back of the book is placed upon it, and the strip is worked backwards and forwards on the roller, which gives it the semicircular shape. It is then dried hard before the fire. Another method is to paste a number of pieces of paper in succession upon a roller, and when thoroughly dry it is cut down lengthwise, thus forming two semicircular backs. Thin sheet-iron is sometimes used for the purpose. The milled boards are then cut out for the side covers. In large books it is usual to glue together two thin boards for each cover, and to insert between them the projecting ends of the vellum bands on which the book is sewn. The first and last fly-leaves are pasted to the boards, and after they are squared, the curved back above described is placed on, and a piece of canvass sufficient to extend over half the width of the book on one side to the same distance on the other side, is glued on the boards and over the back: this holds the hollow back firmly in place. The book is then ready for covering, for which purpose the leather is carefully pared all round and neatly put on. The covers are usually forril and vellum, white and coloured; smooth and rough calf and sheep; basil, smooth and grained, and russia. Forril and vellum covers are lined with paper and pressed smooth. When dry, they are fitted on the back and creased in the joints: the boards are then pasted and the covers pressed on them: when dry, the edges of the cover are pasted and turned in and the book again pressed: the cover is then washed with a sponge and paste-water, and then ruled off. If the cover be rough calf or sheep, it is dressed with pumice-stone and a clothes-brush. Smooth calf, basil, &c., are glaired and polished as in bookbinding. Rough calf books are usually ornamented by passing a very hot roller round the edges and sides of the cover. Large books are sometimes furnished with bands of russia leather worked on with thongs of vellum, which add to the strength of the binding and have a neat appearance. BORACIC ACID. BORAX. [See BORON.] BORING may be regarded as a branch of TURNING; but in the former the tool is generally made to revolve while the work remains stationary, while in the latter the work revolves while the tool is stationary or nearly so. There are, however, exceptions to this, as in boring or forming the cylindrical cavity of ordnance both methods are adopted; in one, the gun revolves and the borer advances in a fixed axis, and by another method the gun is fixed and the cutter revolves. The former is adopted for brass guns, and as the gun revolves, its exterior surface is turned. Cannon are now always cast solid, and the cylindrical cavity is formed by boring into this solid mass. The gun is placed horizontally in the boring. mill, and is fixed to the axis of the mill by means of the square piece at the cascabel. In a boringmill constructed by Smeaton, the gun is placed on the horizontal axis of a water-wheel, and consequently | applied at right angles to the axis of the gun. The revolves with the same velocity. On this same axis, Fig 186 is a toothed wheel which works two wheels, narrow side of the bar is sharpened to a cutting edge, so as to have the form of one tooth of a very large saw, and this being opposed to the direction of the revolving motion of the gun, takes off an angular portion at right angles to the axis, until the cylindrical part connecting the head with the gun is so much diminished that the head falls off with the blow of a hammer. The boring is then commenced by exposing the revolving gun to the action of a steel cutter fixed to the end of a bar placed on a carriage and impelled continually towards the gun. The carriage, which slides in triangular iron grooves, consists merely of a bar on which the rack is pressed forward by the pinion P, Fig. 187, whose gudgeons are on a fixed frame BB, and this pinion works into a rack R. The axis of the pinion has mortised holes in it, through which, one end of the lever L is passed, and the other end is loaded with a weight w, which causes the pinion to propel the carriage and thus urge the boring bar towards the gun. In some machines, two pinions are attached to the same one placed on each side, and on the axis of each of these is a gun of smaller size. A bar of steel in shape and size like the coulter of a plough, is first axis and act on two racks. In other cases the a cylindrical surface. When the bore is of the carriage is propelled by two upright levers, the end proper size and sufficiently true, a bit without a of one of which has a weight hanging from a rope point and rounded off to the desired curve is used passing over a pulley: the lower end of the upper to form the bottom of the chamber. The cutters lever acts on the upper end of the lower, while the become magnetic in consequent of being continually lower extremity of the lower lever presses forward rubbed in the same direction, and the boring dust the carriage. This method is free from any in- is seen hanging from their edges when they are equalities arising from the teeth of the rack. Ac- withdrawn. While the boring is being conducted cording to another contrivance, a screw acting on in this way, the exterior of the gun is turned by the end of the carriage is used to propel it. The appropriate turning tools. A wooden gauge or cutboring bar used in all these machines is a very strong out profile of the gun with its intended mouldings wrought-iron bar of less diameter than the calibre, is applied from time to time to ascertain when the in order to allow the iron dust and shavings to be turning has been continued to the proper depth. readily got out; its diameter is increased for some The cyphers and arms cast on the gun are finished inches near the end B, Fig. 188, where there is a groove by a chisel. The touch-hole is drilled by stock and for admitting the steel cutter bit, or by drill and bow. The gun is then examined T, the two upper angles of to ascertain whether the bore is free from holes : which are cut off obliquely so this is done with an instrument consisting of several as to form an obtuse angled elastic steel prongs with sharp points arranged in drill, the edges of which coming in contact with the a circle: by moving this backwards and forwards revolving metal produce a conical cavity by taking in various ways, the points press against the side, and off shavings from the solid metal. The first bore thus detect any hole that may exist. A lighted wax is smaller than the intended size. When this is taper is also introduced, or the light of the sun is completed, a second borer, consisting of a cross bit reflected by a mirror into the bore, by which means or rectangular piece of steel, with a cutting edge at defects can be detected and examined by eye. The each end, is put through a hole in the boring bar, gun is proved by firing it with a large charge of and the edges of this cutter in revolving describe powder, and also by forcing water into the bore Fig. 188. B T M 2 through a powerful force pump, the touch-hole being stopped. All these precautions in boring and ascertaining the accuracy of the bore have greatly contributed to the present precision in artillery practice. The boring of muskets and small arms will be more conveniently described in connexion with the processes concerned in the manufacture of GUN BARRELS. The boring of cylinders for steam engines, blowing machines, working-barrels of large pumps, and other hollow cylinders of cast-iron in which pistons work, requires very powerful and accurate machinery. The cylinder is cast hollow, and the object of the boring machine is to convert the interior into a true cylinder. The machine shown in Fig. 189, was contrived at the time when accurately bored cylinders were required, in consequence of Watt's improvement in steam engines. In this arrangement the cylinder Fig. 189. is placed horizontally, while the cutters revolve and advance by the action of some powerful prime mover, and the operation is commonly repeated three times, in the last of which the greatest care is required, and the engine is worked from the beginning to the end of the operation. This is also done, by some makers, in the finishing process of boring ordnance, the machine being kept at work through meal-times, day and night; for if it were discontinued while the cutter was only midway or in any part of its journey, and the cylinder allowed to lose the heat it acquires by the friction of the cutter, &c., a ridge and unevenness would be formed in the surface, which would greatly interfere with its proper action. In the boring engine, Fig. 189, s s are two solid sills of oak, arranged parallel to each other and to sleepers let into the ground; at each end is a vertical iron frame, F F, for supporting gudgeons at the end of a long cylindrical axis or tube of cast-iron A A, which revolves by the prime mover. The cylinder c to be bored, is fixed over this bar on an adjusting framing B, and is supported by blocks below, and held fast by iron bands drawn down by screws in the top of standards. The cylinder is adjusted so as to be concentric with the axis A, and is held firmly by wedges driven under the blocks and standards. On this axis slides a cutterhead or piece of cast-iron, RT, Fig. 190, into which are fixed cutters cc. The tube A, shown separately in Fig. 191, is divided by a longitudinal R T Fig. 190. R in the ends of the sliders R, and a bolt passing through the holes in the middle of the sliders at the end of the toothed rack R; a key put through the end of the bolt prevents the rack from being drawn back, and holds the cross-bars in place. The rack is worked by the teeth of the pinion P, and is kept in place by the roller o. The axis of the pinion and roller is attached to the standard F, Fig. 189, and the pinion is turned round by the action of the weight w at the end of a lever on the square end of the axis. By another contrivance, four small wheels are fixed at the right hand of A, Fig. 192. Another pinion fixed to the extremity of the axis, similar to the rack R, has at its other extremity a small screw, which works an interior screw fixed to the cutters R at b. Below the second pinion is another fixed on a horizontal axis parallel to A. At the other end of the axis is a fourth pinion driven by the first at the end of the hollow axis A. As the axis a revolves, the first pinion at its extremity drives the fourth, which by means of the third, fixed on the same axis with it, gives motion to the second; the second pinion, being fixed on an axis within F, unscrews the screw at the other extremity and makes the cutters advance along the cylinder. Sixty turns of the axis cut one inch of the cylinder. According to Billingsley's method, the cylinder is placed with its axis in a vertical instead of a hori zontal position, in order that the boring dust and shavings may fall out instead of wearing and impeding the cutters. By this arrangement the cylinder is bored throughout without changing the cutters, and a more regular bore is thus obtained. Another advantage is, that the cylinder does not deviate from its cylindrical form by its own weight, which sometimes happens when large and slender cylinders are laid on their side. There is also often a loss of shape by improperly strapping and wedging down. Before the general introduction of cast-iron waterpipes, there was a great demand for wooden pipes, which were formed by boring the trunks of trees. For this purpose the tree was well secured to a carriage, and a vertical spindle, driven by a trundle A and face wheel, gave motion to a horizontal bar, | In the centre of this hole the boring is carried on by carrying a borer or auger at its extremity. As this two workmen assisted by a labourer above. The revolved, motion was given to another wheel, about handle of the borer has a female screw in the bottom whose shaft was a rope also attached to the carriage, of its iron shank, into which the boring chisel is so that as the borer cut, the tree was gradually fixed, and a wooden bar or rail passing through its drawn up to the work until the hole was cut socket, with a ring at the top. If the ground be through. A larger auger was then used, and the tolerably soft, the weight of the two men bearing operation repeated until the bore was of the proper upon the cross-bar, and occasionally turning it round, size. In some cases the tree was made to revolve will soon cause the chisel to penetrate; but in rocky against a fixed auger. In other cases the tree was strata the chisel is struck down with repeated blows, fixed vertically, so that the chips could fall out as so as to peck its way, the men frequently shifting the work proceeded. An ingenious machine was also their position, so that the chisel or auger may concontrived for cutting out the core whole, so that it stantly have a fresh place to act upon, by which could be applied to other uses. In this case a hollow means the rock is broken and penetrated. cylinder was formed, with a crown saw at the ex- labour is greatly assisted by an elastic wooden pole, tremity, which, being made to revolve, cut its way placed horizontally over the well, from which a chain into the tree, while the core entered the cylinder, and is brought down and attached to the ring of the was thus preserved whole. A plan of this kind was handle. This pole is made fast at one end, by being patented by Mr. Murdock in 1810 for boring stone- set in a heap of loose heavy stones; at the other end pipes, the core forming round pillars of stone. An the workman gives it a slight up-and-down motion, attempt was made to use the pipes as the common corresponding to the beating motion of the men water-pipes of London; they were joined together below, by which means, the elasticity of the pole, in by means of Parker's cement, but the vibration com- rising, lifts the handle, and thus diminishes the labour municated to the roads by the carriages, loosened the of the men. When the hole has, in this way, been joints and made the pipes leak. opened as far as the length of the chisel will allow, it This A variety of boring tools, used in the arts, will be is withdrawn, and a sort of cylindrical auger, furnished found noticed under AUGER. with an internal valve, shewn in section, Fig. One of the most important applications of boring, 194, is let down for drawing up the dirt and loose stones; the auger being introduced Fig. 194 rods are thus drawn up about 7 feet at Fig. 195. |