The statute gives the court power "upon bill in equity filed by any party aggrieved, to grant injunctions according to the course and principles of courts of equity." (k) This remedy of injunction is that which is usually sought by a * party vv desiring to prevent a violation of his right under a patent. It is a common remedy in equity, and the rules of proceeding and the principles which determine the granting of an injunction, generally, are applied in patent cases; and they cover the matters of pleading, evidence, notice, and the like.

The injunction can issue only to a party who has a legal interest in, or title to, a valid patent. And the question has been much discussed, When will a court grant an injunction without requiring that the plaintiff should first establish this legal right? This question is always addressed to the discretion of the court. But while this discretion is always exercised with a careful regard to the especial facts, circumstances, and merits of the case before the court, it is always guided by such principles as have been established by the practice of the court. What these are we can best show in the words used by courts in leading cases presenting this question; and these we give in our notes. (l)

(j) Whittemore v. Cutter, 1 Gall. 429; Kneass v. Schuylkill Bank, 4 Wash. 9.

(k) Act 1870, § 55.

(l) "The rule as to granting or continuing injunctions in patent-right causes," says Leavitt, J., "is now well settled by the modern usages of the courts of the United States. They are now granted without a previous trial at law, in cases where the owner of the patent shows a clear case of infringement, and has been in the possession and enjoyment of the exclusive right for a term of years without any successful impeachment of its validity. Such possession and enjoyment, aided by the presumption arising from the patent itself, are usually regarded as sufficient to warrant an injunction to restrain an infringement. And there is no fixed rule as to the length of time the possession and enjoyment of the right under a patent shall have continued. It must be sufficient to justify a presumption in favor of its validity. But the presumptions in favor of a patent, arising from the length of time which has elapsed since its issue, are greatly strengthened by the fact, that its validity has been afww * It may be added that laches on the part of the plaintiff, consisting in his long neglect of his right, and so permitting another party to go on spending time and money on what may afterwards be declared an infringement, is always a strong reason against a temporary injunction. (m) And whenever bonds to keep an account of manufacture, sale, profits, etc, will answer the purposes of justice as well, or, perhaps, nearly as well, as a temporary injunction, they are preferred. (n) firmed and sustained by prior judicial decisions, either at law or in equity." Potter v. Muller, 2 Fish. 466. And in Ogle v. Ege, 4 Wash. 584, Washington, J., says: "I take the rule to be in cases of injunction in patent cases that, when the bill states a clear right to the thing patented, which, together with the alleged infringement is verified by affidavit, if the patentee has been in possession of it by having used or sold it, in part, or in the whole, the court will grant an injunction, and continue it until the hearing, or until further order, without sending the plaintiff to law to try his right. But if there appears to be a reasonable doubt as to the plaintiff's right, or the validity of the patent, the court will require the plaintiff to try his title at law. And says Grier, J., "No interlocutory injunction should issue unless the complainant's title and the defendant's infringement are admitted, or are so palpable and clear that the court can entertain no doubt upon the subject." Parker v. Sears, 1 Fish. 93. See also Goodyear v. N. J. Cent R. R. 1 Fish. 626; Muscan Hair Man. Co. v. Amer. H. M. Co. 1 Fish. 320; Tappan v. Nat Bank-note Co. 2 Fish. 196; Doughty v. West, 2 Fish. 633; Hussey v. Whitely, 2 Fish. 120; Foster v. Moore, 1 Curt. 286; Orr v. Littlefield, 1 Wood. & M. 13; Washburn v. Gould, 3 Story, 170; Brooks v. Bicknell, 4 McLean, 72; North v. Kershaw, 4 Blatchf. 70; Hill v. Thompson, 8 Meriv. 622; Caldwell v. Van Vliessingen, 9 Hare, 415; Neilson v. Thompson, Webst. Pat. Cas. 277. But where a sufficient exclusive possession is established it has been held, that a doubt concerning the validity of a patent will not necessarily prevent an injunction. Sargent v. Seagrave, 2 Curt. 555; Isaacs v. Cooper, 4 Wash. 260. The principle that exclusive possession for a time strengthens the title of the patentee is founded on the idea that, as it is a claim of right adverse to the public, and the public acquiesce in that claim, such acquiescence raises a presumption that the claim is good. It was held, therefore, that where the invention was one which few persons would use, and which had not been used in a public manner, no such presumption would arise. Tappan v. Nat Bank-note Co. 2 Fish. 196. And, on the same principle, where the plaintiff's machines were made under several distinct patents, one of which had been repeatedly sustained, it was held that exclusive possession raised no presumption of the validity of the other patents, especially as it appeared that a prejudice had existed against the plaintiff's machine, which it required long time and expense to overcome. Grover & Baker S. M. Co. v. Williams, 2 Fish. 133. Nor in an application for an injunction is the court bound by the result of a previous trial at law, but will examine the whole case, and grant the injunction or not according to its own judgment. Sickles v. Youngs, 3 Blatchf. 293; Many v. Sizer, 1 Fish. 31. See on this subject of injunction, Hodge v. Hudson River R. R. Co. 6 Blatchf. 166; Morris v. Lowell Manuf. Co. 3 Fish. Pat. Cas. 67; Potter v. Whitney, id. 77; Brammer v. Jones, id. 340; Goodyear v. Mullee, id. 420; Goodyear v. Housinger, 3 Fish. Pat Cas. 147.

(m) Wyeth v. Stone, 1 Story, 282; Union Man. Co. v. Lounsbury, 2 Fish. 389; Cooper v. Matthews, 8 Law Rep. 416.

(n) "In acting on applications for temporary injunctions to restrain the infringement of letters-patent," says Judge Curtis, "there is much latitude for discretion. The application may be granted or refused unconditionally, or terms may be imposed on either of the parties as conditions for making or refusing the order. And the state of litigation where the plaintiff's title is denied, the nature of the improvement, the character and extent of the infringement complained of, and the comparative inconvenience which will be occasioned to the respective parties by allowing or denying the motion, must all be considered in deter mining whether it should be allowed or refused; and, if at all, whether abso*The injunction sought for as a permanent and ef xx fectual remedy, is a perpetual injunction. This will be granted only on a final hearing. It may be sought for on purely legal grounds. But if sought on grounds of fact, and the fact be denied, as if for an infringement and this be denied, then the facts at issue must, generally at least, be tried by a jury. (o) But, as in other cases, the jury will be instructed by the court; and, if the verdict be manifestly erroneous, it will be set aside. It may be, however, that the question of infringement may rest upon the construction of documents, or otherwise on merely legal grounds, and is wholly within the province of the court.

The question whether an injunction can be issued in one country for a violation there of a right under a patent issued there, when the violation is by a foreigner bringing with him what was lutely, or upon some and what condition." In this case an account was directed to be kept. In Tatham v. Lowber, 4 Blatchf. 86, Nelson, J., says: "It is common in the case of a bill filed for an infringement, and a motion made for a preliminary injunction, where the question of infringement is not manifest, and enjoining the defendant would produce serious hardship or derangement of his business, to withhold the injunction on defendant's keeping an account or giving security for damages accruing." And this is done especially where the defendant is merely using a patented machine, and the plaintiff has been in the habit of licensing parties to make such use of it, as the amount of the license fee is then the measure of the plaintiff's damages. In such a case Judge Grier says: "A chancellor who would issue an injunction to stop a mill or manufactory, locomotive or steam engine, because in their construction some patented device or machine has been used, would act with more than doubtful discretion. Stopping the mill or steam engine might inflict irreparable injury, but could not benefit the inventor. The compensation to him for this trespass on his rights is the price of a license. The wrong done him is not the use of his invention, but the non-payment of a given sum of money. To issue an injunction in such a case, where neither prevention nor protection is sought or required, would be an abuse of power. An injunction is not to be used as an execution, or for extortion." Sanders v. Logan, 3 Wall. Jr. 2 Fish. 197. See also Livingston v. Jones, 2 Fish. 207; Foster v. Moore, 1 Curt 279;

Orr v. Littlefield, 1 Wood. & M. 13; Bay v. Candee, 3 Fish. 9.

But where the infringement is clear, and the right to an injunction manifest, the injunction will not be stayed on the defendant's offer to keep an account, although it may occasion irreparable injury to the defendant, and though the latter be well able to respond in damages. Sickles v. Mitchell, 8 Blatchf. 648; Tracy v. Torry, 2 Blatchf. 279; Gibson v. Van Dresar, 1 Blatchf. 686; Forbush v. Bradford, 21 Law Rep. 471.

(o) This, though the usual course, is not invariably so. Thus in Goodyear v. Day, 2 Wall. Jr. 283, Grier, J., says: "It is true that in England the chancellor will generally not grant a final and perpetual injunction in patent cases, when the answer denies the validity of the patent, without sending the parties to law to have that question decided. But even there the rule is not absolute or universal. It always rests on the sound discretion of the court. A trial at law is ordered by a chancellor to inform his conscience; not because either party may demand it as a right, or that a Court of Equity is incompetent to judge of questions of fact, or of legal titles. In the courts of the United States, the practice is by no means so general as in England, or as it would be here if the trouble of trying issues at law devolved upon a different court." See Sickles v. Gloucester Man. Co. 1 Fish. 222; Woodworth v. Rogers, 3 Wood. & M. 149; Van Hook v. Pendleton, 1 Blatchf. 194; Buchanan p. Howland, 6 Blatchf. 161; Bacon v. Jones, 4 My. & Cr. 433.

• 257 yy lawfully made and used and sold in the country of the foreigner, has been answered in England in the affirmative; (r) yy *and in this country quite as positively, and we think for better reasons, in the negative. (q)