224 FEDERAL REPOSTEB. �devîce is \ïithin or without the lîcense ; and what the plaintiff calls a neglect and refusai to keep the agreement, is an honest difference of opinion as to its true seope. TJbe agreement in this case gives the plaintiffs the great advantage of terminating the agreement in case' of default, if they please; but only when they shall have served a certain written notice. Until after that has been done they are not entitled to profits and damages, but to royalties ; the account and injunotion which they might bave are both different from those which they ask for. I see no propriety or legality in adding a forfeiture by implication to that which the parties have provided by their eontract. �It is true, as the plaintiffs contend, that if a licensee has f enounced the license he may, on the one hand, defend against the agreement and set up the invalidity of the patent ; and, on the other, may be treated as an infringer. Moody v. Taber, 1 Holmes, 325; Cohn v. National Rubber Co. 15 Off. Gaz. 829. The mistake is in supposing that anything less than au unequivocal renunciation will work this effect. "No renunci- ation of the permission, warning the plaintiffs that the defend» ants meant to claim to use the invention in their own right, is averred," Lawes v. Purser, 6 E. & B. 930, 934. That was a case in which the patentee was insisting on the eontract; but no court of equity will say that a plaintifif, even if he bave an election to put an end to a eontract in a certain way, shall assume it to be ended without following that method, and proceed accordingly. This eontract still exists until one party or the other, or both, bring it to an end. It cannot be treated as ended, as a legal consequence of a failure to pay the royalties. To this effect are the authorities, even before the late and controlling case cf Hartell v. Tilghman, 99 U. S. 547. Bee Wilson v. Sand/ord, 10 How. 99; Hartskorn v. Day, 19 How. 211 ; Goodyear v. Union R. Co. 4 Blatohf. 63 ; Blanchard T. Sprague, 1 Cliff. 288; Merserole v. Union Paper Collar Co. 6 Blatchf. 356-7. �If, then, there were no clause in the agreement providing for the mode of putting an end to it by notice, and that the royalties should be the measure of damages until notice was ����
