Books have lately been bound without any sewing, by “Hancock’s Patent” process. This consists in having all the sheets folded into double leaves, and the folded parts all brought evenly to a curved form for the back of the book by means of a mould or hollow cut in the edges of two upright boards (fig. 5); they are then removed to a press which holds the book tightly together, leaving this curved back just projecting in front of the press-boards. The back is smeared with India-rubber dissolved in naptha, which when dry is several times repeated, till a coating of sufficient thickness is produced, when it is covered with cloth or linen and the book is ready to be finished in the usual way; thus the sewing is quite dispensed with, for the folded edge of each sheet is held to the next one by a thin coating of India-rubber. This plan allows great freedom in opening, and for thick books produces a level surface much superior to those bound in the old way (figs. 6 and 7). PAPER-STAINING. Illustration: “GROUNDING” THE PAPER. This name is given to the process for making paper-hangings for the decoration of the walls of apartments. The colors used in this process are all what are called body-colors, or those which are not transparent, but mixed with whiting or prepared chalk and a small quantity of size to the required tint. The colors are applied by means of wooden blocks having their surfaces so engraved that the pattern shall project; all the pattern is not engraved on one block, but only that part of it which is to be of one color, and the number of blocks required depends upon the number of colors in the pattern--usually three or four. The paper is printed in pieces of about twelve yards in length; these are first “grounded,” that is, colored all over with the color intended to form the ground of the pattern, and hung on poles to dry. The blocks are applied to a sort of sieve, with a leather bottom, on which some color is spread with a brush, and when the block is taken up sufficient of the color adheres to give a good impression on the paper. Each block has a register, which produces a little mark at the edge of the paper, and serves as a guide in applying the succeeding blocks, so that when printed they fit into and correspond with each other. Illustration: PRINTING THE PATTERN. “Flock” paper is produced by printing part of the pattern in a varnish of boiled oil and whiting, and laying the paper so printed in a trough or tray over which the flock is sprinkled. The flock is made by grinding shreds of cloth of the required color in a mill. This rough surface gives a very rich and velvety appearance to the paper. FLAX MANUFACTURE.