SEVEEAL MECHANICAL INVENTIONS. 167 



entire mission, and this I could only bear for a few 

 months. 



Besides his printing and transferring apparatus, Mr. 

 Perkins brought over several other new and interesting in- 

 ventions and discoveries, both mechanical and philosophical, 

 which created much inquiry in the scientific and artistic 

 circles of London. Among the mechanical novelties was 

 the " Geometrical Lathe," a triumph of skill in forming, by 

 cutting or etching, minute intersecting lines on cylinders 

 for printing delicate shades of gradual tints on grounds of 

 paper or cloth. 



The new plans for engraving designs, and the many 

 improvements he had made in the machinery for trans- 

 ferring by steel dies, were patented as improvements 

 on the former patent, which had then some four years 

 to run. 



After some time the late Mr. Charles Heath, of high 

 artistic celebrity, was induced to join Mr. Perkins, and by 

 a purchase of a share in the patents, became an active 

 partner in the engraving and printing works, which were 

 then commenced in Fleet Street, London, and have since 

 been continued by their successors. 



It was found here, as in America, that to make an inven- 

 tion of importance, and to secure it to its author by patent, 

 is not enough to protect him in its exercise in peace and 

 quietness. When at length Perkins's steel engraving had 

 been taken up by several banks and publishers, and was 

 beginning to yield him some fame and profit, other artists 

 soon appeared to compete with him for both, claiming to 

 have done the same work long before him ! 



If the " transferring process " described in the patent 

 of 1810 had in fact been practised before that time by the 

 parties who, ten years later, denied his right as the original 

 inventor, how came it to pass that no practical application 



