BOOKBINDING. There are several and distinct branches of this business,— plain and ornamental binding,—law bind mg,—blank book and ledger binding ; the latter is a department in itself, and usually conducted by stationers.
The various sizes of a book are desig nated by the number of leaves in which the sheet is folded : thus folio is 2 leaves ; quarto, 4 leaves ; octavo, 8 leaves ; duo decimo, 12 to a sheet ; and so on to the smallest sizes of 24mo and 32mo. After the sheets of a book have been folded, they are collated by the leumeral or letter placed at the foot of the first page in the first sheet, in order to ascertain that the work is perfect. The next process is that of pressing : this is done in a hydraulic press. Tke back of the sheets is then sawed by machine, after which the sewing process com mences. This last is a qmck operation, as a girl can sew three thousand sheets a day. The middle of the sheets are stitched with thread to the upright cords fastened on the press ; as soon as one sheet is fastened to all the strings, ano ther is laid down on it, and fastened in a similar manner. India-rubber binding supersedes the necessity of sewing, bind ing every leaf as securely, and giving greater flexibility.
When the sewing is finished the strings are cut, leaving an inch or so banging, which are used to, fasten the book to its case. The backs &f the sheets are now all glued to increase the connection.
By hammering on wooden blocks, or better still, by passing the sheets be tween rollers, the back is rounded and the front hollowed out, and a grooved hollow made, into which the millboard is fitted, the covers being fastened by the strings through the boards. The book is
next placed between boards and screwed up in a press, with one of its ends pro jecting. The ends of the leaves are now cut off a plough, the cutting edge of which, in its action, is midway between a knife and a plane-iron. When books are bound in leather, the sides of the covers are previously stamped with a de vice, or embossed as it is termed. The embossing machine sometimes exerts a pressure of 50 tons. The devices on the back, edges, and margin, are placed on by hand with a revolving wheel, which has on its edge the device cut out, and which leaves its impression when the wheel is rolled along.
Gutty percha has lately been introduced into binding, to imitate the antique old oak binding.
When books are to be gilt, the edges are scraped and burnished with the agate burnisher, then colored over with red bole or chalk, ground in soap, rubbed in fine paper, and twain well burnished this brightens up the gilding. The gold leaf is then cut into slips, and laid on. Gilding on marbled edges has a very beautiful effect, as the marbling is per ceived through the gold.
Several of the book binderies in New York, Philadelphia, and Boston, employ from fifty to one hundred persons, in cluding females who stitch and fold.