38 



of the plate gave an impression of his. design. After this 

 he tried the effect of moistened paper pressed down on 

 the engraving with a roller, and met with complete suc- 

 cess. For some time he used the discovery to make 

 copies of his designs. Finally other engravers and gold- 

 smiths penetrated his secret, and soon the important dis- 

 covery was widely diffused. 



Copper and steel.-plate engraving, as now practised, is 

 subdivided into five branches, viz., line, stipple, mezzo- 

 tint, aquatint and etching. Pure line engraving is one of 

 the most difficult and tedious methods used for the pur- 

 pose of illustration, and has given place, of late years, 

 to more expeditious and less costly modes of work. A 

 plate of copper or steel, the latter metal being preferred 

 on account of its greater durability, comes from the man- 

 ufacturer ready for the engraver's use. The plates are 

 prepared with a perfectly sound texture and even grain 

 throughout, and the surface is perfectly smooth and very 

 highly polished. For copper plates the price asked is 

 about twenty-five cents per square inch, so that the first 

 cost of the plate alone is sometimes a considerable 

 amount. The engraver, having received the plate ready 

 for use, must transfer to it a careful outline of the picture 

 he proposes to engrave. To this end, the plate is first 

 heated until it attains a sufficient uniform heat to melt 

 white wax, a piece of which is rubbed over it, and allowed 

 to spread in a thin layer till the whole surface is equally 

 covered, after which the plate is left in a horizontal posi- 

 tion, until the wax is cold. In the interval a careful 

 tracing of the original design is made with black lead 

 pencil upon thin tracing paper, and this is afterwards 

 spread over the surface of the waxed plate, with the lead 

 lines in contact with it, and of course reversed. The 

 tracing being secured in this position, heavy pressure is 



