¶1delivered the opinion of the Court:
¶2Without reviewing the evidence at length, as was done by the several tribunals of the Patent Office, we agree that, as between McArthur and Whitall, the decision is correct.
¶3On this appeal Whitall contends that McArthur is concluded by the case of Lloyd v. Anlisdel, 17 App. D. C. 490. If the question of originality had been between Blaw and McArthur, the latter might be estopped, but that is not the case, and it does not appear how Whitall can avail himself of the estoppel. *26Whitall also seeks to escape the effect of his signature to the caveat, on the ground that the same did not disclose the ribs of the issue. It appears that these were well known to both McArthur and Whitall at the time, and that it was understood to be part of the construction. Moreover, the ribs had been used in other construction well known, and were at the time public property. It is clear that when Whitall signed the caveat he knew that it contained substantially all of the design work which Whitall and McArthur had presented to the attention of the contractors engaged in the construction' of the New York aqueduct.
¶4The Examiners in Chief noted the limitation put upon Blaw by his preliminary statement, and it is said that this point might be waived by McArthur.
¶5Holding that Blaw was limited by that statement, McArthur was awarded priority over Blaw.
¶6The Examiner of Interferences had decided in favor of Blaw on the ground that McArthur could not claim the .reduction to practice that was made by the Blaw company at the time of his employment, and that he was not diligent in reducing to practice; wherefore Blaw Avas awarded priority.
¶7The Examiner held that McArthur’s employment was by Blaw, and that the reduction to practice could not redound to his benefit, as Blaw was his employer. The Examiners in Chief found that both Blaw and McArthur were employees of the Blaw company; that McArthur had only recognized Blaw’s claim of priority to the extent that he took the word of Blaw and the word of the executive officers of the company to the effect that BlaAv conceived the invention at a date before .he did, and that this was not the recognition of an adverse right of an employer, and does not, therefore, constitute an estoppel against McArthur. They further held that the Blaw company Avas in effect from the beginning the assignee of McArthur, and any reduction to practice by the BlaAv company in Avhich McArthur had a part should accrue to the benefit- of McArthur. The BlaAv company reduced the inA-ention to practice. The record shows that the reduction to practice did not commence *27until after McArthur came into the employment of the company, and that without question it show's that McArthur was the moving spirit and designer in this reduction to practice. Therefore it was held that he was entitled to the reduction to practice, whereupon they reversed the Examiner of Interferences, and awarded priority to McArthur.
¶8Afterwards Tic Arthur waived the protection afforded to him by Blaw’s preliminary statement with respect to his date of disclosure, and agreed that, in so far as McArthur is concerned, Blaw should be entitled to any date of disclosure which the Commissioner of Patents should find has been adequately proved by Blaw’s record. On appeal to the Commissioner, he affirmed the finding as between Tic Arthur and "Whitall, and refused to consider the waiver of McArthur of the date of the preliminary statement of Blaw, and affirmed the decision awarding priority to McArthur.
¶9The matter of permitting an amendment to a preliminary statement is one that is in the discretion of the Commissioner of Patents, and there seems to be no abuse of it in this instance. The Commissioner was also right in not entertaining the waiver of McArthur because Whitall was still á party and was also affected by that waiver, notwithstanding the finding of the Examiner of Interferences and the Examiners in Chief.
¶10"With that statement in the way, Blaw’s evidence of an earlier conception was not entitled to consideration, and therefore the award to Ale Arthur was right.
¶11The decision is affirmed, and the clerk will certify this decision to the Commissioner of Patents as required by law.
¶12Affirmed.