95. Lettering books. The gilt letters on the backs of books are formed by placing a piece of gold leaf upon the leather, and pressing upon it brass letters previously heated: these cause the gold immediately under them to adhere to the leather, whilst the rest of the metal is easily brushed away. When a great number of copies of the same volume are to be lettered, it is found to be cheaper to have a brass pattern cut with the whole of the proper title: this is placed in a press, and being kept hot, the covers, each having a small bit of leaf-gold placed in the proper position, are successively brought under the brass, and stamped. The lettering at the back of the volume in the reader's hand was executed in this manner. 96. Calico printing from blocks. This is a mode of copying, by surface printing, from the ends of small pieces of copper wire, of various forms, fixed into a block of wood. They are all of one uniform height, about the eighth part of an inch above the surface of the wood, and are arranged by the maker into any required pattern. If the block be placed upon a piece of fine woollen cloth, on which ink of any colour has been uniformly spread, the projecting copper wires receive a portion, which they give up when applied to the calico to be printed. By the former method of printing on calico, only one colour could be used; but by this plan, after the flower of a rose, for example, has been printed with one set of blocks, the leaves may be printed of another colour by a different set. 97. Printing oilcloth. After the canvas, which forms the basis of oilcloth, has been covered with paint of one uniform tint, the remainder of the processes which it passes through, are a series of copyings by surface printing, from patterns formed upon wooden blocks very similar to those employed by the calico printer. Each colour requiring a distinct set of blocks, those oilcloths with the greatest variety of colours are most expensive. There are several other varieties of printing which we shall briefly notice as arts of copying; which, although not strictly surface printing, yet are more allied to it than that from copperplates.