United States Mitis Co. v. Carnegie Steel Co.

ACHESON, Circuit Judge.

The bill charges the defendant with the infringement of letters patent No. 333,373, for an improvement in “the process of manufacturing castings from wrought iron and steel by adding aluminium,” dated December 29, 1885, and issued to Thorsten Nordenfelt, assignee of Carl Gustav Wittenstrom, the inventor. The specification of the patent begins by pointing out that “one of the great difficulties in making castings from steel is to get a product which is solid, sound, homogeneous, or free from blisters or cavities.” It refers to recent improvements in the art of steel…