doubts relevant to the question should be resolved against infringers,' because it is improbable that men will render themselves liable to actions for infringement, unless infringement is useful." 1 Whitney v. Mowry, 4 Fisher, 215, 1870. 2 * Lehnbeuter v. Holthaus, 105 U. S. 94, 1881; La Rue v. Electric Co. 31 Fed. Rep. 82, 1887. CHAPTER V. ABANDONMENT. 86. The several sorts of abandon- 87. Abandonment of inventions. 89. Actual abandonment by express 90. Actual abandonment by formal disclaimer. 91. Actual abandonment resulting from laches before application. 92. Actual abandonment resulting from laches after application and before issue of letters patent. 93. Constructive abandonment before application. 94. "Public use," defined and delineated. 95. Experimental use. 96. "On sale," delineated and defined. 97. Sale of inchoate right to a pat ent. 98. Degree of identity necessarily involved between the thing constructively abandoned and the thing patented. 99. Making, works no constructive 100. Public knowledge works no 103. Constructive abandonment af ter application, and before issue of letters patent. 104. Rules of constructive abandonment are inflexible. 105. Surrender of letters patent. 106. Abandonment of invention af ter letters patent, unknown to 107. Acquiescence in unlicensed use § 86. AN inventor may abandon an unsuccessful endeavor to make an invention; or having made an invention, he may abandon it to the public; or having made an invention and having applied for a patent thereon, he may abandon that application without abandoning that invention. Transactions of the first sort are commonly called unsuccessful abandoned experiments. They confer no rights upon those who make them, and they affect no rights of any other person.' Transactions of the third sort are treated in the chapter on applications: the sixth chapter of this book. Transactions of the second sort require treatment in respect that they are inventions; and also require separate treatment in respect that they are abandoned. Treatment of the first sort takes no account of the fact of abandonment, because abandoned inventions have the same effect on the rights of subsequent inventors that they would have if they had not been abandoned. That subject, therefore, does not belong to this chapter. It is treated in the chapters on invention and letters patent, where the state of the art is a very important factor in the discussion; and also in the chapter on novelty, where anticipation is the point of inquiry. Treatment of the second sort indicated above is the special function and scope of this chapter. Abandoned inventions are here considered with regard to the effect abandonment of them has upon the rights of their inventors, and with regard to the rules by means of which abandonment is to be affirmed or denied in particular cases. § 87. Abandonment of an invention may be actual, or it may be constructive. It is actual when it is the result of intention. It is constructive when it is the result of some statute which operates regardless of the intention of the inventor. The two sorts require and will receive separate treatment in this chapter, but there are some points of fact and of law which apply equally to both. Either kind may occur before any application for a patent is made, or may occur after such an application, and before any letters patent are issued.' So also, either actual or constructive abandonment of an invention, is fatal to the validity of any patent that may afterward be granted therefor. The inchoate right to a patent when once abandoned can never be resumed, for where gifts are once made to the public, they become absolute and irrevocable." 'American Bell Telephone Co. . Cushman Telephone Co. 35 Fed. Rep. 734, 1888. Rifle & Cartridge Co. v. Arms Co. 118 U. S. 24, 1885. 3 Pennock v. Dialogue, 2 Peters, 1, 1829; Kendall v. Winsor, 21 Howard, 328, 1858; Consolidated. Fruit $88. Actual abandonment of an invention occurs whenever there is an entire relinquishment of all expectation of securing a patent therefor, and an accompanying formation of an expectation that the invention will always be free to the public. Such a relinquishment may be shown by direct, or by circumstantial evidence. It may be proved by things said or things done by the inventor, or it may be proved by his omission or delay to do what the law requires to be done in order to secure letters patent. § 89. An inventor abandons his invention to the public when he makes an express declaration to that effect." In the case of Pitts v. Hall,' Justice NELSON charged the jury to the contrary of this rule, but it is believed that he never was followed in this respect by any other Federal judge. Subsequently Justice CURTIS charged the jury, in Kendall v. Winsor, that abandonment might be shown by declarations or conduct, and the Supreme Court held that Justice CURTIS's instruction was in strict conformity with the true principle. The Supreme Court also said in that case: "It is the unquestionable right of every inventor, to confer gratuitously the benefits of his ingenuity upon the public, and this he may do by express declaration." $ 90. So also an inventor will no doubt be held to abandon a particular invention, when he formally disclaims it in an application for a patent for some other invention; and by sameness of reasoning, when he formally disclaims it in a separate paper filed for that purpose. The Supreme Court decided in 1854, that no abandonment results from the mere fact that the inventor described the invention in an application for a patent, without either claiming or disclaiming the same. When the cited case was tried in the Jar Co. v. Wright, 94 U. S. 96, 1876; Co. v. Arms Co. 118 U. S. 24, Planing Machine Co. v. Keith, 101 1885. U. S. 484, 1879; Consolidated Fruit Jar Co. v. Stamping Co. 27 Fed. Rep. 377, 1886. 1 Babcock v. Degener, 1 McArthur's Patent Cases, 616, 1859. 2 Kendall v. Winsor, 21 Howard, 328, 1858; Rifle & Cartridge 1851. Pitts . Hall, 2 Blatch. 237, 4 Leggett v. Avery, 101 U. S. 259, 1879. 5 Battin v. Taggert, 17 Howard, 83, 1854. court below, the judge charged the jury "That a description, by the applicant for a patent, of a machine, or a part of a machine, in his specification, unaccompanied by a notice that he has rights in it as an inventor, or that he desires to secure title to it as a patentee, is a dedication of it to the public." But when the case reached the Supreme Court, that instruction was decided to be erroneous, and a new trial was therefore awarded. The paramount precedent thus established has, however, been overlooked in many recent cases, beginning with Miller v. Brass Co., in 1882. In that case, Justice BRADLEY wrote the following obiter dictum: "But it must be remembered that the claim of a specific device or combination, and an omission to claim other devices or combinations apparent on the face of the patent, are in law a dedication to the public of that which is not claimed." That obiter dictum was contrary to what the Supreme Court decided in the case of Battin v. Taggert, and like the obiter dictum of the same Justice in the case of Carr v. The United States, which was afterwards mentioned and overruled by the Supreme Court in the case of the United States v. Lee,' it has no force as law. The rule in Battin v. Taggert therefore remains unreversed, and has been enforced in several cases in the Circuit Courts, even since Miller v. Brass Co. was published.* § 91. Abandonment is also proved by evidence that the inventor is chargeable with laches, relevant to applying for a patent, or relevant to prosecuting or renewing his application after it has been rejected or withdrawn." Long delay constitutes laches, unless there was some reason which rendered that delay consistent with an expectation to 1 Miller v. Brass Co. 104 U. S. 352, 1881. * Carr v. United States, 98 U. S. *433, 1878. 3 United States v. Lee, 106 U. S. 217, 1882. 4 Vermont Farm Machine Co. v. Marble, 19 Fed. Rep. 307, 1884; Cahn . Wong Town On, 19 Fed. Rep. 424, 1884. 5 Consolidated Fruit Jar Co. v. Wright, 94 U. S. 96, 1876; Craver v. Weyhrich, 31 Fed. Rep. 607, 1887. • Planing Machine Co. v. Keith, 101 U. S. 484, 1879; Rifle & Cartridge Co. v. Arms Co. 118 U. S. 22, 1885. |