ing the antenna circuits is one of the principles which were well understood and stated by Stone himself before Marconi, and the mechanism for achieving which had previously been disclosed by Lodge and Stone, 18 [2] Since no invention over Stone was involved in tuning the antenna circuits, neither Marconi nor Stone made an invention by providing adjustable tuning of any of the circuits or by employing Lodge's variable inductance as a means of adjusting the tuning of the resonant four circuit arrangement earlier disclosed by Stone's application and patented by him. No invention was involved in employing the Lodge variable inductance for tuning either the closed or the open circuits in lieu of other structural modes of adjustment for that purpose. The variable inductance imparted no new function to the circuit; and merely making a known element of a known combination adjustable by a means of adjustment known to the art, when no new or unexpected result is obtained is not invention. Peters v. Hanson, 129 U. S. 541, 550-51, 553, 47 O. G. 945; Electric Cable Co. v. Edison Co., 292 U. S. 69, 79, 80, 445 O. G. 271, and cases cited; Smyth v. Sheridan, 149 Fed. 208, 211; cf. Bassick Co. v. Hollingshead Co., 298 U. S. 415, 424–5, 469 O. G. 3, and cases cited. Stone's conception of his invention as disclosed by his patent antedated his application. It is carried back to June 30, 1889, seven months before his application, when, in a letter to Baker, he described in text and drawings his four-circuit system for wireless telegraphy in substantially the same form as that disclosed by the application. His letter is explicit in recommending the tuning of the antenna circuits. In part he wrote as follows: Instead of utilizing the vertical wire [antenna] itself at the transmitting station as the oscillator, I propose to impress upon this vertical wire, oscillations from an oscillator, which oscillations shall be of a frequency corresponding to the fundamental of the wire. Similarly at the receiving station, I shall draw from the vertical wire, only that component of the complex wave which is of lowest frequency. If now the fundamental of the wire at the receiving station be the same as that of the wire at the transmitting station, then the receiving station may receive signals from the transmitting station, but if it be different from that of the transmitting station, it may not receive those signals. 18 It is not without significance that Marconi's application was at one time rejected by the Patent Office because anticipated by Stone, and was ultimately allowed, on renewal of his application, on the sole ground that Marconi showed the use of a variable inductance as a means of tuning the antenna circuits, whereas Stone, in the opinion of the Examiner, tuned his antenna circuits by adjusting the length of the aerial conductor. All of Marconi's claims which included that element were allowed, and the Examiner stated that the remaining claims would be allowed if amended to include a variable inductance. Apparently through oversight, claims 10 and 11, which failed to include that element, were included in the patent as granted. In allowing these claims the Examiner made no reference to Lodge's prior disclosure of a variable inductance in the antenna circuit. The tuning of these circuits one to another and all to the same frequency will probably be best accomplished empirically, though the best general proportions may be determined mathematically. On July 18, 1899, Stone again wrote to Baker, mathematically demonstrating how to achieve the single frequency by means of forced vibrations. He expressed as a trigonometric function the form taken by the forced wave "if the period of the impressed force be the same as that of the fundamental of the vertical wire." He also pointed out that the transmitting circuit which he had disclosed in his earlier letter to Baker, "is practically the same as that employed by Tesla," except that Stone added an inductance coil in the closed circuit "to give additional means of tuning" and to "swamp" the reactions from the coil of the oscillation transformer and thus loosen the coupling between the open and closed circuit of the transmitter.19 His recognition of the effect upon the current in the antenna if it is of the same period as the charging circuit; his statement that his transmitting system was the same as that employed by Tesla; his recognition that the fundamental of the receiver should be the same as that of the transmitter antenna when used for the transmission of a single frequency, and finally his statement that all four circuits are to be tuned, "one to another and all to the same frequency," all indicate his understanding of the principles of resonance and of the significance of tuning the antenna circuits. Stone disclosed his invention to others, and in January, 1900, described it to his class at the Massachusetts Institute of Technology. Before 1900 he was diligent in obtaining capital to promote his invention. Early in 1901 a syndicate was organized to finance laboratory experiments. The Stone Telegraph & Telephone Co. was organized in December, 1901. It constructed several experimental stations in 1902 and 1903; beginning in 1904 or 1905 it built wireless stations and sold apparatus, equipped a Navy collier and some battleships, and it applied for a large number of patents. The apparatus used in the stations is described by Stone's testimony in this suit as having resonant open and closed circuits loosely couples inductively to each other, at both the transmitter and receiver, and all tuned to the same wave length, as described in his letters to Baker and his patent. [3] We think that Stone's original application sufficiently disclosed the desirability that the antenna circuits in transmitter and receiver be resonant to the same frequency as the closed circuits, as he expressly recommended in his patent. But in any event it is plain that no departure from or improper addition to the specifications was involved in the 1902 amendments, which merely made explicit what was already implicit. Hobbs v. Beach, 180 U. S. 383, 395–7, 94 O. G. 2357. We would ordinarily be slow to recognize amendments made 19 See footnote 13, supra. after the filing of Marconi's application and disclosing features shown in that application. Cf. Schriber-Schroth Co. v. Cleveland Trust Co., 305 U. S. 47, 57, 498 O. G. 277; Powers-Kennedy Corporation v. Concrete Co., 282 U. S. 175, 185-6, 402 O. G. 517; Mackay Radio Co. v. Radio Corporation, 306 U. S. 86, 501 O. G. 567. But here Stone's letters to Baker, whose authenticity has not been questioned in this case, afford convincing proof that Stone had conceived of the idea of tuning all four circuits prior to the date of Marconi's invention. Cf. Bickell v. Smith-Hanbury-Scott Welding Co., 53 F. 2d 356, 358. [4] It is well established that as between two inventors priority of invention will be awarded to the one who by satisfying proof can show that he first conceived of the invention. Philadelphia & Trenton Ry. v. Stimpson, 14 Pet. 448, 462; Loom Co. v. Higgins, 105 U. S. 580, 593, 21 O. G. 2031; Radio Corporation v. Radio Laboratories, 293 U. S. 1, 11–13, 445 O. G. 535; Christie v. Seybold, 55 Fed. 69, 76, 64 O. G. 1650; Automatic Weighing Mach. Co. v. Pneumatic Scale Corp., 158 Fed. 415, 417-22, 139 O. G. 991; Harper v. Zimmermann, 41 F. 2d 261, 265; Sachs v. Hartford Electric Supply Co., 47 F. 2d 743, 748. [5] Commercial success achieved by the later inventor and patentee cannot save his patent from the defense of anticipation by a prior inventor.20 Compare Smith v. Hall, 301 U. S. 216, 481 O. G. 211, with 20 Even if the lack of invention in Marconi's improvement over Stone-making adjustable the tuning of the antenna circuits which Stone had said should be tuned-could be said to be in sufficient doubt so that commercial success could aid in resolving the doubt, Thropp's Sons Co. v. Seiberling, 264 U. S. 319, 330, 27 O. G. 441; De Forest Radio Co. v. Electric Co., 283 U. S. 664, 685, 408 O. G. 83; Altoona Theatres v. Tri-Ergon Corp., 294 U. S. 477, 488, 452 O. G. 705, it has not been established that the alleged improvement contributed in any material degree to that success. Compare Altoona Theatres v. Tri-Ergon Corp., supra. Marconi's specifications disclose a large number of details of construction, none of which is claimed as invention in this patent, in which his apparatus differed from, and may have been greatly suprior to, Stone's. Many of these formed the subject of prior patents. After his application for this patent, as well as before, Marconi made or adopted a great number of improvements in his system of wireless telegraphy. Two of his engineers have written that a major factor in his successful transmission across the Atlantic In December, 1901, was the use of much greater power and higher antennae than had previously been attempted, an improvement in no way suggested by the patent here in suit. Fleming, Electric Wave Telegraphy, 449-53; Vyvyan, Wireless Over Thirty Years, 22-23. Indeed both are agreed that in the actual transmission across the Atlantic tuning played no part; the receiver antenna consisted of a wire suspended by a kite which rose and fell with the wind, varying the capacity so much as to make tuning impossible. Ibid. By 1913, when he testified in the National Electric Signalling Co. case, that “due to the utilization of the invention" of this patent he had successfully transmitted messages 6,600 miles, he had, after almost continuous experimentation, further increased the power used, developed new apparatus capable of use with heavy power, enlarged his antennae and adopted the use of horizontal, “directional" antennae, and made use of improved types of spark gaps and detecting apparatus, including the Fleming cathode-anode tube, the crystal detector, and sound recording of the signals-to mention but a few of the improvements made. He had also discovered that much greater distances could be attained at night. See Vyvyan, supra, 34-47, 55-60. The success attained by the apparatus developed by Marconi and his fellow engineers by continuous experimentation over a period of years— however relevant it might be in resolving doubts whether the basic four circuit, tuned system disclosed by Marconi, and before him by Stone, involved invention-cannot, without further proof, be attributed in significant degree to any particular one of the many improvements made by Marconi over Stone during a period of years. The fact that Marconi's apparatus as a whole was successful does not entitle him to receive a patent for every feature of its structure. Smith v. Snow, 294 U. S. 1, 451 O. G. 487. To obtain the benefit of his prior conception, the inventor must not abandon his invention, Gaylor v. Wilder, 10 How. 477, 481, but must proceed with diligence to reduce it to practice. We think Stone has shown the necessary diligence. Compare Radio Corporation v. Radio Laboratories, supra, 13, 14. The delay until 1902 in including in his patent specifications the sentences already referred to, which explicitly provide for tuning of the antenna circuits, does not in the circumstances of this case show any abandonment of that feature of Stone's invention since, as we have seen, the idea of such tuning was at least implicit in his original application, and the 1902 amendments merely clarified that application's effect and purport. Marconi's Patent No. 763,772 was sustained by a United States District Court in Marconi Wireless Telegraph Co. v. National Signalling Co., 213 Fed. 815, and his invention as specified in his corresponding British Patent No. 7777 of 1900, was upheld in Marconi v. British Radio & Telegraph Co., 27 T. L. R. 274, 28 R. P. C. 18. The French court likewise sustained his French patent, Civil Tribunal of the Seine, Dec. 24, 1912. None of these courts considered the Stone patent or his letters. All rest their findings of invention on Marconi's disclosure of a four circuit system and on his tuning of the four circuits, in the sense of rendering them resonant to the same frequency, in both of which respects Stone anticipated Marconi, as we have seen. None of these opinions suggests that if the courts had known of Stone's anticipation, they would have held that Marconi showed invention over Stone by making the tuning of his antenna circuit adjustable, or by using Lodge's variable inductance for that purpose. In Marconi Wireless Telegraph Co. v. Kilbourne & Clark Mfg. Co., 239 Fed. 328 affirmed 265 Fed. 644, the district court held that the accused device did not infringe. While it entered formal findings of validity which the Circuit Court of Appeals approved, neither court's opinion discussed the question of validity and that question was not argued in the Circuit Court of Appeals.21 21 A preliminary injection restraining infringement was entered in Marconi Wireless Tel. Co. v. De Forest Tel. & Tel. Co., 225 Fed. 65, affirmed, 225 Fed. 373, both courts, without independent discussion of the validity of the patent, determining that the decision in the National Signaling Co. case justified the grant of preliminary relief. A preliminary injunction was also granted against the Atlantic Communications Company. Stone's letters were introduced in evidence in the Atlantic Communications Company case and the Kilbourne and Clark case. His deposition in the latter case, taken February 28 and 29, 1916, was incorporated in the record in this case. He there testified that he had refrained from producing proofs of the priority of his invention when called upon to testify in prior litigation in 1911 and 1914 because he wished the priority of his invention to be established by the owners of the patent-the Stone Telegraph Co. and its bondholders-in order to be sure that a bona fide defense would be made. He said that by 1915 or 1916, when he testified in the Atlantic Communications Co. case, he had concluded that the owners of the patent were not in a financial position to litigate, and that the Atlantic Co. "would make a bona fide Stone defense." [6] Marconi's reputation as the man who first achieved successful radio transmission rests on his original patent, which became Reissue No. 11,913, and which is not here in question. That reputation, however well-deserved, does not entitle him to a patent for every later improvement which he claims in the radio field. Patent cases, like others, must be decided not by weighing the reputations of the litigants, but by careful study of the merits of their respective contentions and proofs. As the result of such a study we are forced to conclude, without undertaking to determine whether Stone's patent involved invention, that the Court of Claims was right in deciding that Stone anticipated Marconi, and that Marconi's patent did not disclose invention over Stone. Hence the judgment below holding invalid the broad claims of the Marconi patent must be affirmed. In view of our interpretation of the Stone application and patent we need not consider the correctness of the court's conclusion that even if Stone's disclosures should be read as failing to direct that the antenna circuits be made resonant to a particular frequency, Marconi's patent involved no invention over Lodge, Tesla, and Stone. Claim 16 of Marconi Patent No. 763,772 The Government asks us to review so much of the decision of the Court of Claims as held valid and infringed claim 16 of Marconi's Patent No. 763,772. That claim is for an antenna circuit at the receiver connected at one end to "an oscillation-receiving conductor" and at the other to a capacity (which could be the earth), containing the primary winding of a transformer, "means for adjusting the two transformer-circuits in electrical resonance with each other," and "an adjustable condenser in a shunt connected with the open circuit, and around said transformer-coil." Marconi thus discloses and claims the addition to the receiver antenna of an adjustable condenser connected in a shunt around the primary of the transformer. The specifications describe the condenser as "preferably one provided with two telescoping metallic tubes separated by a dielectric and arranged to readily vary the capacity by being slid upon each other." Marconi, however, makes no claim for the particular construction of the condenser. Although the claim broadly provides for "means of adjusting the two transformer-circuits in electrical resonance," Marconi's drawings disclose the use of a variable inductance connected between the aerial conductor and the transformer-coil in such a manner that the variable inductance is not included in that part of the antenna circuit which is bridged by the condenser. The condenser is thus arranged in parallel with the transformer coil and in series with the variable in |