State Savings Institution of St. Louis (Kilbourne v.) 22 Howard, 503... 428 Statham (Callan v.) 23 Howard, 477... 667 Sturgis v. Clough, 21 Howard, 451.. 88 Sun Mutual Insurance Company v. Wright, 23 Howard, 412.. 622 V. Vallejo (United States v.) 22 Howard, 416......................... 392 Vallette (White Water Valley Company v.) 21 Howard, 414 66 Verden v. Coleman, 22 Howard, 192. 287 Vermont and Massachusetts Railroad Company (White v.) 21 Howard, 575..... 181 Very v. Watkins, 23 Howard, 469................. 661 W. Wakefield (Brewster v.) 22 Howard, 118...... Walker (United States v.) 22 Howard, 299... v. Smith, 21 Howard, 579.... Wallace (Commissioners of Knox County v.) 21 Howard, 456... v. Chamberlain, 21 Howard, 572... v. Thompson, 22 Howard, 330........ Watkins (Very v.) 23 Howard, 469.. 256 344 183 161 162 162 361 661 559 Westbrook (Gridley v.) 23 Howard, 503.. 686 Western Telegraph Company v. Penniman, 21 Howard, 460.. White's Administratrix (United States v.) 23 Howard, 249... 522 v. Wright, Williams & Co., 22 Howard, 19....... 214 v. Vermont and Massachusetts Railroad Company, 21 Howard, 575.... 181 White Water Valley Company v. Vallette, 21 Howard, 414... Wright (Sun Mutual Insurance Company v.) 23 Howard, 412.. Yontz v. United States, 23 Howard, 495...... Yturbide's Executors v. United States, 22 Howard, 290...... Z. Zabriskie v. Cleveland, Columbus, and Cincinnati Railroad Company, 23 Howard, 381........ 680 337 604 GEORGE KENDALL and others, Plaintiffs in Error, v. JOSEPH S. WINSOR. 21 H. 322. PATENT LAW-DELAY IN OBTAINING PATENT. 1. While an inventor is experimenting with and perfecting his invention, if he voluntarily permits its use by the public, with no attempt to conceal or protect his invention, a party making one of his machines may lawfully use it after the patent has been issued. 2. But if the inventor has endeavored to conceal his invention, and has asserted his design to secure a patent as soon as perfected, one who has surreptitiously obtained knowledge which enables him to construct and use the invention is liable as an infringer if he continue this use after the patent has been obtained. 3. The question of the abandonment of the invention by the inventor to the public, THIS is a writ of error to the circuit court for the district of 21h 322 L-ed 165 129 205 Kendall v. Winsor. Rhode Island. The instruction of the court complained of, and all the facts and pleadings, are fully set forth in the opinion. Mr. Jenckes, for plaintiffs in error. Mr. Keller, for defendant. [* 323 ] *Mr. Justice DANIEL delivered the opinion of the court. This was an action on the case in the circuit court of the United States, instituted by the defendant in error against the plaintiffs, for the recovery of damages for an alleged infringement by the latter of the rights of the former as a patentee. No question was raised upon the pleadings or the evidence in this case as to the originality or novelty of the invention patented, nor with respect to the identity of that invention with the machine complained of as an infringement of the rights of the patentee, nor as to the use of that machine. These several facts were conceded, or at any rate were not controverted, between the parties to this suit. Under the plea of not guilty, the defendant in the circuit court gave notice of the following defenses to be made by him: 1. A license from the plaintiff to use his invention. 2. A right to use that invention in virtue of the seventh section of the act of congress of the 3d of March, 1839, which section provides, "That every person or corporation who has or shall have purchased or constructed any newly-invented machine, manufacture, or composition of matter, prior to the application of the inventor or discoverer for a patent, shall be held to possess the right to use, and vend to others to be used, the specific machine, manufacture, or composition of matter, so made or purchased, without liability therefor to the inventor or any other person interested in such invention." To the relevancy and effect of the evidence adduced with reference to the two defenses thus notified, and to the questions of law arising upon the issues made by those defenses, this controversy is properly limited. Upon the trial in the circuit court, in support of this defense, evidence was introduced tending to show that the plain[* 324] * tiff constructed a machine in substantial conformity with his specification as early as 1846, and that in 1849 he had several such machines in operation, on which he made harness. to supply all such orders as he could obtain; that he continued to run these machines until he obtained his letters patent; that he repeatedly declared to different persons that the machine was so complicated that he preferred not to take a patent, but to rely on |