And in order to produce this print, it must be borne in mind that each sheet of paper has to be passed as many times through the press as there are stones, since each stone imprints upon it only its own particular section of the work. Of course, in proportion to the increase in the number of the stones, does the difficulty increase of making the work upon each fall exactly upon its proper place in the general design; for, if any one were misplaced only the fiftieth of an inch, the drawing and colour of the whole would be disturbed. Hence it is found necessary to arrange the _register_, or adjustment of the stones, with the utmost care and precision, and to exercise the most careful supervision in the printing, since the sheet of paper expands considerably in passing through the press, and has to be dried and re-damped before it can be passed through again. But practically this is all accomplished with seeming ease, and a large and most complex subject will be found, when the last stage has been reached, to bear the most minute scrutiny; and the result, even when the copy is placed alongside the original, will surprise and delight equally those who have followed the work through its several steps and those who may only examine the completed work. Of late, many chromos have been beautifully printed from prepared blocks on an ordinary cylinder-press. ENGRAVING. [Illustration] The invention of wood engraving has been claimed for the Chinese, whose books have certainly been printed from engraved wood blocks for ages. It is not, however, until the beginning of the fifteenth century that we find any evidence of the existence of wood engraving as we now understand it. It is probable that Italy was the first European country to make engravings, but only for printing playing-cards. Holland and Germany soon applied the art to better ends. The earliest print of which any certain information can be obtained is in the collection of Earl Spencer. It was discovered in one of the most ancient convents of Germany,—the Chartreuse of Buxheim, near Memmingen in Bavaria,—pasted within the cover of a Latin MS.; it represents Saint Christopher carrying the infant Saviour across the sea, and is dated 1423. We give a reduced fac-simile of this curious engraving. The inscription at the bottom has been thus translated:— In whichever day thou seest the likeness of St. Christopher, In that same day thou wilt, at least from death, no evil blow incur.—1423. [Illustration]