The claims, of whose infringement complaint was made, read thus: "(1) The combination, with a source of alternating currents and a circuit from the same, of a motor having independent energizing circuits connected with the said circuit, and means for rendering the magnetic effects due to said energizing circuits of different phase and an armature within the influence of said energizing circuits. "(2) The combination, with a source of alternating currents and a circuit from the same, of a motor having independent energizing circuits connected in derivation or multiple arc with the said circuit, the motor or energizing circuits being of different electrical character, whereby the alternating currents therein will have a difference of phase, as set forth. "(3) The combination, with a source of alternating currents and a circuit from the same, of a motor having independent energizing circuits connected in derivation or multiple arc with the said circuit and of different active resistance, as set forth. "(4) In an alternating current motor, the combination, with field magnets. of independent energizing currents, adapted to be connected in multiple arc with the conductors of the line or transmission circuit and a resistance or selfinduction coil in one or both of the said motor circuits, as set forth." In connection with the defense of double patenting, claim 5 is brought into the case: "(5) In an alternating current motor, the combination, with the field magnets or cores, of independent energizing coils adapted to be connected in multiple arc with the line or transmission circuit, and a variable resistance or self-induction coil included in one or both of the motor circuits, as set forth." If the patents are valid, appellant concedes infringement. The defenses are anticipation, want of invention, double patenting, and prior foreign patenting. Respecting anticipation, the facts, as we find them to be, are summarized in the opinion. As no anticipation is found, the prior art, with notice of which Tesla was chargeable, is limited to his own polyphase motor, referred to in the patents in suit, and to Overbeck's laboratory demonstration of the equivalency of three modes of producing two alternating currents of differing phases, one mode being by the use of a two-phase generator, and the other two being by splitting a single current and causing the part in one branch (either induced or derived) to lag. In one of appellant's briefs Overbeck's experiments and appellant's application of them to the patents in suit are diagramed thus: The defense of double patenting is founded on a comparison of the patents in suit, particularly claim 5 and Fig. 7 of No. 511,560, with Tesla's patent No. 401,520, issued April 16, 1889, on an application filed February 18, 1889, for a "method of operating electro-magnetic motors." The specification of No. 401,520 states: "As is well known, certain forms of alternating-current machines have the property, when connected in circuit with an alternating-current generator, of running as a motor in synchronism therewith; but, while the alternating current will run the motor after it has attained a rate of speed synchronous with that of the generator, it will not start it. Hence, in all instances heretofore where these 'synchronizing-motors,' as they are termed, have been run, some means have been adopted to bring the motors up to synchronism with the generator, or approximately so, before the alternating current of the generator is applied to drive them. In some instances mechanical appliances have been utilized for this purpose. In others special and complicated forms of motor have been constructed. I have discovered a much more simple method or plan of operating synchronizing-motors, which requires practically no other apparatus than the motor itself. In other words, by a certain change in the circuit-connections of the motor I convert it at will from a double-circuit motor, or such as I have described in prior patents and applications, and which will start under the action of an alternating current, into a synchronizing-motor, or one which will be run by the generator only when it has reached a certain speed of rotation synchronous with that of the generator. In this manner I am enabled to very greatly extend the applications of my system and to secure all the advantages of both forms of alternating-current motor. "The expression 'synchronous with that of the generator' is used herein in its ordinary acceptation; that is to say, a motor is said to synchronize with the generator when it preserves a certain relative speed determined by its number of poles and the number of alternations produced per revolution of the generator. Its actual speed, therefore, may be faster or slower than that of the generator; but it is said to be synchronous so long as it preserves the same relative speed. "In carrying out my invention I construct a motor which has a strong tendency to synchronism with the generator. The construction which I prefer for this is that in which the armature is provided with polar projections. The field-magnets are wound with two sets of coils, the terminals of which are connected to a switch mechanism, by means of which the line-current may be carried directly through the said coils or indirectly through paths by which its phases are modified. To start such a motor, the switch is turned onto a set of contacts which includes in one motor-circuit a dead resistance, in the other an inductive resistance, and, the two circuits being in derivation, it is obvious that the difference in phase of the current in such circuits will set up a rotation of the motor. When the speed of the motor has thus been brought to the desired rate, the switch is shifted to throw the main current directly through the motor-circuits, and although the currents in both circuits will now be of the same phase the motor will continue to revolve, becoming a true synchronous motor." * * "I believe that I am the first to operate electro-magnetic motors by alternating currents in any of the ways herein suggested or described; that is to say, by producing a progressive movement or rotation of their poles or points of greatest magnetic attraction by the alternating currents until they have reached a given speed, and then by the same currents producing a simple alternation of their poles, or, in other words, by a change in the order or character of the circuit-connections to convert a motor operating on one principle to one operating on another, for the purpose described.” And the claims are these: "(1) The method of operating an alternating current motor herein described by first progressively shifting or rotating its poles or points of greatest attraction, and then, when the motor has attained a given speed, alternating the said poles, as described. "(2) The method of operating an electro-magnetic motor herein described, which consists in passing through independent energizing-circuits of the mo tor alternating currents differing in phase, and then, when the motor has attained a given speed, alternating currents coinciding in phase, as described. "(3) The method of operating an electro-magnetic motor herein described, which consists in starting the motor by passing alternating currents differing in phase through independent energizing-circuits, and then, when the motor has attained a given speed, joining the energizing-circuits in series and passing an alternating current through the same. "(4) The method of operating a synchronizing-motor, which consists in passing an alternating current through independent energizing-circuits of the motor and introducing into such circuits a resistance and self-induction coil, whereby a difference of phase between the currents in the circuits will be obtained, and then, when the speed of the motor synchronizes with that of the generator, withdrawing the resistance and self-induction coil, as set forth." The defense of prior foreign patenting is based on section 4887, U. S. Rev. St. [U. S. Comp. St. 1901, p. 3382], as it stood when the patents in suit were issued: "Sec. 4887. No person shall be debarred from receiving a patent for his invention or discovery, nor shall any patent be declared invalid, by reason of its having been first patented or caused to be patented in a foreign country, unless the same has been introduced into public use in the United States for more than two years prior to the application. But every patent granted for an invention which has been previously patented in a foreign country shall be so limited as to expire at the same time with the foreign patent, or, if there be more than one, at the same time with the one having the shortest term, and in no case shall it be in force more than seventeen years." The foreign patent on account of which the patents in suit are said to have expired is British patent No. 6,527 of 1889. It is substantially the same as the domestic patent No. 401,520. The patents here in suit, as well as the basic patents relating to the rotating-field motor-principle, have been in litigation repeatedly. In connection with the voluminous record and briefs we have read the following cases: Westinghouse Co. v. Granite Co. (C. C.) 103 Fed. 951; Westinghouse Co. v. Granite Co., 110 Fed. 753, 49 C. C. A. 151; Westinghouse Co. v. Royal Weaving Co. (C. C.) 115 Fed. 733; Westinghouse Co. v. National Electric Co. (C. C., E. D. Wis., not reported); Tesla Electric Co. v. Scott & Janney (C. C.) 97 Fed. 588; Westinghouse Co. v. Dayton Co. (C. C.) 106 Fed. 724; Dayton Co. v. Westinghouse Co., 118 Fed. 562, 55 C. C. A. 390; Westinghouse Co. v. Catskill Co. (C. C.) 94 Fed. 868; Westinghouse Co. v. Catskill Co. (C. C.) 110 Fed. 377; Westinghouse Co. v. Catskill Co. (C. C.) 121 Fed. 831; Westinghouse Co. v. Stanley Co. (C. C.) 129 Fed. 140; Westinghouse Co. v. Stanley Co., 133 Fed. 167, 68 C. C. A. 523; Westinghouse Co. v. Stanley Co., 138 Fed. 823, 71 C. C. A. 189; Westinghouse Co. v. Roberts (C. C.) 125 Fed. 6; Westinghouse Co. v. Mutual Life Ins. Co. (C. C.) 129 Fed. 213; Westinghouse Co. v. Electric Appliance Co. (C. C.) 133 Fed. 397; Westinghouse Co. v. Electric Appliance Co. (C. C.) 142 Fed. 545; Jefferson Co. v. Westinghouse Co., 139 Fed. 385, 71 C. C. A. 481. Appellant's counsel urge their case with thoroughness and zeal, and they properly insist upon their right to our independent judgment of the merits of each defense as now presented. Charles A. Brown and Charles E. Pickard, for appellant. Before GROSSCUP, BAKER, and SEAMAN, Circuit Judges. BAKER, Circuit Judge (after stating the facts). Applications for the patents in suit were filed on December 8, 1888. Shallenberger on April 20, 1888, and Ferarris on April 22, 1888, made disclosures that void these patents unless the fact be that Tesla made the improvements in question at an earlier date. May 15, 1888, Tesla applied for patents, which were granted as Nos. 555,190 and 511,915, on the inductive splitphase motor. This form was then regarded by Tesla and his attorney as more important than the derivative split-phase motor. Shortly afterwards the Westinghouse Company began negotiations for the purchase of the Tesla motor inventions; arrangements were consummated in July; and Tesla thereupon went to Pittsburg to instruct the Westinghouse engineers. Delay from May to December is thus accounted for. Tesla has no pecuniary interest in this litigation. His testimony is positive that he operated the "Exhibit Motor" in all of the ways involved in these patents as early as September, 1887. The "Exhibit Motor," as we understand it to have stood in September, was a rotating-field motor, the ends of whose windings were loose. These four wires could be coupled to the four wires of a two-phase alternating current generator, and the motor would then run in the manner described in the basic patents of May 1, 1888. These four wires could also carry, in turn, each of the phase-splitting means covered by the patents in suit, and when so equipped could be coupled to the two wires of a single-phase alternating current generator, and the motor would then run as an inductive or a derivative split-phase motor. So the exhibit is not regarded as proving anything beyond its capability of having built into it the phase-splitting devices. But the prolonged cross-examination, in our judgment, does not derogate in the least from the direct testimony that the exhibit was used as stated. Brown, an electrical engineer, in 1887 and 1888 was financially concerned in the inventions that Tesla was then making. He has no interest in this litigation. When Tesla showed him the polyphase motor, designed to be coupled to the four wires of a two-phase generator, he raised the objection that it would not work in connection with the systems of single-phase generators and line-wires which were then in general use throughout the country. His testimony is positive that shortly afterwards, in the "summer" or "summer or fall" of 1887, Tesla fully disclosed the methods and means of the split-phase motor by the use of the "Exhibit Motor." We are not impressed by the parallel columns of alleged discrepancies between his testimony and that of Tesla. Advocates' argument is familiar that if witnesses agree in details their stories have been fixed up, and if they disagree in details. neither is to be believed in respect to the vital matters about which they are in accord. So far as we can judge from the printed page, Brown was a reliable witness. It should not be doubted that he saw at some time what he says he saw. The Court of Appeals for the Second Circuit (121 Fed. 831, 58 C. C. A. 167), on a record less complete than that presented here, concluded that Brown was mistaken in the year; that he first saw the split-phase motor in the "summer" or "summer or fall" of 1888. We find that Brown was not mistaken, for these reasons: He fixes the place at Tesla's laboratory, 89 Liberty street, New York. Tesla gave up this laboratory and went to Pittsburg in July, 1888, stayed a year, and when he returned to New York took quarters in a different street; and Brown relates the time to the early days of the polyphase invention. As Tesla began filing applications for split-phase improvements as early as May, 1888, for Brown to have seen for the first time the "Exhibit Motor" operated as a split |