There are two distinct schools of wood engraving, and they are easily recognised from each other whenever either of them is exclusively new, but the large majority of the more recent book illustrations cut on wood show traces of both styles. These styles are firstly that of the black line, the type of which may be found in Caxton’s _Myrrour of the Worlde_ printed in 1481, and secondly that of the white line, the best type of which may be found in the _History of British Birds_, illustrated with engravings by Thomas Bewick in 1797. [Illustration: Page from Caxton’s “Myrrour of the Worlde.” (_London_, 1481.) [_To face p._ 108.] In judging whether an illustration in a book is printed from a block cut and printed in the manner of a wood block, the first thing to observe is whether the black lines are pressed into the paper or not. The amount of the depression of the black lines may be very slight, but it must always be looked for because although the necessary pressure for printing from type and block is slight, still there is always some of it, and before the introduction of the modern clay-laden papers, the paper used for printing upon was always softened by damp, and consequently very susceptible to pressure. If the depression of the black lines can be recognised, the print is made from a block of some sort, and printed with a slight pressure. William Blake’s curious illustrated poems are exceptions to any rule. He was very poor and unable to afford to have his writings properly published, so he wrote and drew them out himself on copper, and then etched away the ground very strongly so as to leave his lines in relief. The plates were then printed as relief blocks. As curiosities they are of great interest, and they preserve the individual touch of the artist to just about the same extent as an etching does. The process is exactly analogous to the manner in which names or designs are etched on sword blades, key rings, knife blades and the like, only Blake allowed the acid to work a little more strongly so as to get a slightly higher relief. The first English printed book that is illustrated is Caxton’s _Myrrour of the Worlde_, printed in 1481; the cuts are quite elementary in character, like all the wood cuts in English books for a long time. Ornamental borders are found in Caxton’s _Fifteen Oes._, printed about 1490. Early English books were not freely illustrated, and it must be supposed that wood cutters were scarce. Many of the cuts used are of foreign origin. One early book is charmingly illustrated in colour; Dame Juliana Bernes’ so-called _Book of St. Albans_, printed in 1486, has a long series of coats-of-arms printed from wood blocks. The colour has been added either from other blocks separately inked or else by means of stencil plates. In the sixteenth century wood illustrations became more numerous, but many of them were still of foreign workmanship.