6 





first to discover the mode of ruling medals, as exhibited by his 



specimen, published in 1817. 



(Signed,) Asa Spencer." 



Philadelphia, Aug. 8, 1830. 



Second certificate. — " I do hereby certify, that in the year 1816, 

 being then employed by Messrs. Murray, Draper, Fairman & Co* 

 in their establishment, with Mr. Gobrecht and Mr. Spencer, I was 

 in the knowledge of the circumstance of Mr. Gobrecht's employ- 

 ing Mr. Spencer to make for him a ruling machine, the plan of 

 which was, that the plate was to be moved under the ruler by 

 means of a screw, and a machine was actually commenced to op- 

 erate on this principle. The screw, however, was abandoned, 

 and the machine was constructed so as to graduate with a roller, 

 and merely to divide and rule straight lines. While this machine 

 was constructing, Mr. Gobrecht explained to me a plan he had 

 invented, to copy, by a ruling machine, medals, and surfaces 

 slightly or deeply undulated, which he wished me to keep a 

 secret, as it might be of great importance, and before June, 1817, 

 he shewed me his machine, with the part attached to copy med- 

 als and surfaces, which was constructed by himself, and in suc- 

 cessful operation. At the same time he shewed a head of Alex- 

 ander, executed by means of the machine. 



(Signed,) D. H. Mason, Machinist and Engraver. 17 



July 26, 1839. 



The above statements establish all the claims of Mr. Gobrecht. 

 You certainly made the ruling machine for him, and doubtless, 

 with your well known skill and ingenuity ; but it was without 

 the appendage necessary to adapt it for medal ruling. Your alter- 

 ation of Mr. Gobrecht's plan of moving the platform, appears to 

 have possessed no advantages ; at any rate, Mr. Saxton has adopt- 

 ed the screw in the last instrument of his construction. 



It surprises us that you make light of Mr. Saxton's device for 

 removing the distortion produced by the original machine-engra- 

 ving ; and that you seem to suppose that the means of overcom- 

 ing this defect, are so obvious as to have occurred " to many be- 

 sides Mr. S. and yourself." Now we think, on the contrary, that 



Mr 



enious 



and by no means obvious. Many sagacious persons who have 

 seen it in operation, have not been able to understand the princi- 

 ple upon which it acts ; and it is certain that the art of medal 



