Electrotyping is an American invention. As long ago as 1830 the laboratory discovery was made that when copper was deposited upon the side of a voltaic battery and then removed, it furnished a reproduction of the surface upon which it had been deposited. In the development of this discovery very interesting experiments in reproduction were performed by Thomas Spencer of Liverpool, J. C. Jordan of London, and Prof. Jacobi, a Russian. These experiments were purely scientific, with no commercial end in view. In 1839 Joseph A. Adams, a wood engraver connected with Harper & Brothers, the New York publishers, conceived the idea of applying this principle to the printing industry and made an electrotype from a wood cut which was used for a magazine illustration in 1841. He also made the illustrations for Harper’s great family Bible, which was published in 1842–1844. Adams’s method was to take an impression of his block in an alloy of soft metal, probably largely bismuth. The process, however, destroyed the block, and although experimentally successful it was not commercially practicable. The invention of Smee’s battery and the use of wax for the moulds made the process commercially sound and practical. In 1848 John W. Wilcox, of Boston, using these methods, began business as the first commercial electrotyper and was successful from the beginning. His first work contained all the essentials known for many years. Improvements soon followed. In 1855 John Gay, of New York, introduced the use of tin foil for soldering the back of copper shells and the same year Adams invented a dry brush black-leading machine to take the place of the hand method which had hitherto been necessary. In 1856 Filmer, of Boston, invented the process of backing up the shells by holding the shell down with springs. In 1868 Stephen D. Tucker invented the type of dry brush black-leading machine which is now in use and ten years later Edward A. Blake, of Chicago, invented the air blast black-leading machine. As early as 1871 Silas P. Knight, of Harper & Brothers, invented the wet black-leading process. It was successful, but, as sometimes happens, attracted no particular attention. Its merits in comparison with other methods do not appear to have been appreciated and the discovery was forgotten for more than a quarter of a century. In 1908 Frank H. Learman, of Buffalo, invented a wet black-leading machine which was adopted by the industry and improved by later patents. The wet process is now considered the best. Perhaps the greatest single step forward in the development of the electrotype was the substitution of the dynamo for Smee’s battery, a change accomplished by Leslie, of New York, in 1872. R. Hoe & Company, of New York, were greatly interested in electrotyping machinery and were leaders in encouraging its development and in putting it on the market. CHAPTER V THE DEVELOPMENT OF PRINTING PRESSES