The owner of a patent acquires a legal monopoly. He needs no contract or combination in restraint of trade to make his monopoly complete and secure. He may keep his invention out of use altogether,25 and may exercise "the power of grant-

24 See supra, Sec.1643, n. 90. 25 Paper Bag Patent Case, 210 U.

S. 405, 52 L. Ed. 1122, 22 & Ct 748 ing it to some and withholding it from others, a right of selection of persons and terms." 26 But the ownership of competing patents by different persons gives them no right to make a monopolistic combination of their rights. Any such combination involving interstate commerce is obnoxious to the Sherman Act,27 and contracts in furtherance of the monopolistic purpose of such a combination are invalid.28 Moreover, there is a limit to the right of a patentee to impose conditions on licenses or grants, or to exact promises in return for them. The conditions or promises must not be illegal, and if they have for their object the creation of a monopoly broader than that granted by the patent, as by subjecting a whole industry to a plan for fixing prices 29 or even for the fixing of resale prices for the patented article itself,30 or for the wholesale admission of the validity of the patents of the licensor,31 the patent laws afford no protection. Whether at common law by contract or condition the purchasers of a patented article can be restricted to the exclusive use of supplies or other goods from the patentee is not so clear.32 Probably this depends on whether such a contract or condition is part of a scheme to obtain a monopoly wider than that of the patented article.33 Certainly this result cannot be achieved by mere notices on patented articles.34 The principles governing copyrighted articles are doubtless similar.35 The Clayton Act has now made

26 United States v. United Shoe Mach. Co., 247 U. S. 32, 62 L. Ed. 968, 38 S. Ct. 473, 482.

27 United Shoe Machinery Co. v. La Chappelle, 212 Mass. 467,99 N. E. 289, Ann Cas. 1913 D. 715. See also United States v. United Shoe Mach. Co., 247 U. S. 32, 62 L. Ed. 968, 38 S. Ct. 473.

28 United Shoe Mach. Co. v. La Chapelle, 212 Mass. 467, 99 N. E. 289, Ann. Cas. 1913 D. 715.

29 Standard Sanitary Mfg. Co. v. United States, 226 U. S. 20, 57 L. Ed 107, 33 S. Ct. 9.

30 Boston Store v. American Graph-ophone Co., 246 U. S. 8, 62 L. Ed. 551, 38 S. Ct. 257, Ann. Cas. 1918 C. 447. See further J 1649.

31 Pope Mfg. Co. v;. Gormully, 144 U. S. 224, 36 L. Ed. 414, 12 Sup. Ct. Rep. 637.

32 That such restrictions may be imposed in a lease of patented machinery as distinguished from a sale was held in United States v. United Shoe Mach. Co., 247 U. S. 32, 38 S. Ct. 473, 62 L. Ed. 968.

33 See supra, Sec. 1645.

34 Motion Picture Patents Co. v. Universal Film Mfg. Co., 243 U. S. 502, 61 L. Ed. 871, 37 S. Ct. 416, L. R. A. 1917 E. 1187, Ann. Cas., 1918, A. 959.

35 See Bobbe-Merrill Co. v. Straus, 210 U. S. 339,52 L. Ed. 1086,28 S. Ct. 722; Scribner v. Straus, 210 U. S. 362, 52 L. Ed. 1094, 28 S. Ct. 735; Straus such contracts by one engaged in Interstate Commerce illegal.36