Statement by Mr. Justice GRAY:

These were two bills in equity, heard together in the circuit court, and argued together in this court.

On March 31, 1886, Allen C. Dalzell, a citizen of the state of New York, and the Fahys Watch-Case Company, a New York corporation, filed a bill in equity against the Dueber Watch-Case Manufacturing Company, a corporation of Ohio, for the infringement of two patents for improvements in apparatus for making cores for watch cases, granted to Dalzell, October 27, 1885, for the term of which he had, on January 21, 1886, granted a license, exclusive for three years, to the Fahys Company.

To that bill the Deuber Company, on June 4, 1886, filed the following plea: That prior to the grant of the said [149 U.S. 315, 316] letters patent upon which the bill of complaint is based, and prior to the application therefor, and prior to any alleged invention by said Dalzell of any part, feature, or combination described, shown, or claimed in either of said letters patent, the said defendant being then engaged in the manufacture of watch cases in t