Treat, J.,(orally.) This is an action upon two patents. The only inquiry involved is as to the infringement by the defendant of plaintiff’s patents. The party defendant did not choose, under the *283requirements of the statute, to assail the validity of the complainant’s patents. Therefore tlie case stands solely on the question of infringement. Both patents are infringed, and there will be a decree accordingly, and perpetual injunction. It may or may not be that defendant’s patent is an improvement; but whether that be so or not, he cannot infringe tho plaintiff’s patents, the validity of which is undisputed. As to the damages, B. Gratz Brown will be appointed special master pro hue vice.