In Ambler v. Whipple, 87 U.S. 546 (1874), the suit was based upon articles of partnership between Ambler and Whipple, by which it was agreed that all patents obtained by either partner should be owned by both in equal shares. The bill alleged that the two jointly had obtained a patent for a joint invention, and that another patent, afterwards obtained by Whipple upon the application of a third person, embodied the same invention with only a colorable variation. Neither of the patents was in the record, and the questions now presented were not suggested by counsel or considered by the court, but the decree for the plaintiff proceeded upon independent grounds.