of which there is a dispute. Sawyer testified that this contract, which was signed by the Strauss Company, contained a provision that he (Sawyer) would assign any invention covering yielding barriers he already had made; that he made a copy of the contract, and submitted the original and copy to an engineer by the name of Leyden, an entirely ^disinterested party, who witnessed the same. Mr. Leyden' testified that Sawyer came to his office and showed him a contract which he proofread with Sawyer. He then was asked whether he would recognize that proposed contract, or’offer of employment, if' he saw it again, and replied in the affirmative. When further asked whether he would recognize the copy made from this proposed contract, he again replied in the affirmative. Thereupon he identified both original and copy. He then was asked how, when he proofread this copy with the original, the copy compared with the original, and answered : “The copy in no way differed from the original contract.” Cross-examination failed in any way to change the testimony of this witness. The testimony of Mr. Sumner, who was present, is corroborative of that of Mr. Leyden.
Mr. Sawyer refused-to sign this proposed contract, and a new contract, eliminating the objectionable provision, was prepared and signed. We are convinced that the original or proposed contract contained the provision testified to by Sawyer and his witnesses. In the first place, it is extremely improbable that such a writing could be the product of imagination, and, in the second place, Mr. Leyden is a gentleman of education and character, whose testimony is not to be discredited without reason. Moreover, the surrounding circumstances are consistent with the testimony. The importance of this item of testimony, of course, is that, if Strauss did npt then believe that Sawyer had the invention, there was no necessity for obligating Sawyer to assign it.
[2] We already have said that Mr. Strauss is an engineer of experience. The record also discloses that he is experienced in patent matters. When, therefore, he prepared his preliminary statement, he must have appreciated fully the importance of accuracy. He had every reason to believe that Sawyer would claim the same invention and that the element of time would be controlling. On oath he stated that he disclosed the invention on the 1st day of October, 1921. Upon the taking of testimony he served notice that he would move to amend his preliminary statement, but no such motion was filed, and, had it been, must have been denied in the circumstances. We have said that it is always a suspicious circumstance when a party to an interference, after seeing his adversary’s dates, attempts to put back his own date as set out in his preliminary statement, and that an amendment upon so important a point should not be allowed unless the interests of justice plainly demand it. Parker v. Appert, 8 App. D. C. 270, 276; Hammond v. Basch, 24 App. D. C. 469, 473; Fowler v. McBerty, 27 App. D. C. 41, 44. In his preliminary statement Mr. Strauss alleges conception in June, but it is significant that when he made that statement he was unwilling to go farther and say that he then disclosed it to any one. In his testimony, however, he was quite certain that he had disclosed it to Kaufman.
Strauss introduced in evidence two sketches, Exhibits Nos. 18 and 23, dated, respectively, September 5 and 12,1921, and signed by himself and a Mr. Hopkins, an engineer in the employ of Strauss Company at the time of the occurrences in question. These sketches disclose the invention, and Mr. Strauss testifies that they weré made on the dates they bear. Mr. Hopkins, however, “could not reconcile the date with the sequence of events,” because “my [his] recollection is that this particular problem was not discussed until after the tests made on the Austin avenue barrier on September 29, 1921.” Mr. Hopkins further testified that he was in New York City from September 6 to 14, 1921, and therefore could not have signed the sketch in Chicago on September 12th. The blueprint, Exhibit No. 19, evidently made from Sketch Exhibit No. 18, bears no date and the original is claimed to have been lost. This is another very suspicious circumstance. If Strauss was in possession of the invention prior to the Austin avenue test on September 29th, the comment of the Examiner of Interferences on this phase of the case is pertinent:
“If Strauss had an adequate conception of the invention and ample faith in a physical embodiment of it as a triumph over the existing difficulties experienced by the continuous breaking of the operating chains, it is unexplained why a suitable device embracing his conception was not incorporated in the Austin avenue barrier, or in the Hudson county barrier testified about by Hopkins. Nor is it explained,, if he already knew the proper remedy of the difficulty, why he sought to learn the details of the cure for the ills that the Austin avenue tests brought