delivered the opinion of the Court:

Appeal from a decision of the Commissioner of Patents in an interference proceeding awarding priority of invention to the senior party, Robert Wahl.

The counts sufficiently explained the invention and read as follows:

“1. As an improvement in the art of brewing fermented malt beverages, involving the preparation of a malt-mash, drawing *292off the wort, and boiling the same with hops, cooling and fermenting, the step which consists in adding to the matter under treatment an extract of malt iff thé form of a liquor acidulated with lactic acid propagated therein.

“2. As an improvement in the art of brewing fermented malt beverages, involving the preparation of a malt-mash, drawing off the wort and boiling the same with hops, cooling and fermenting, the step which consists in adding to the mash an extract of malt in the form of a liquor acidulated with lactic acid propagated therein.”

Ludwig Braun relies for conception and constructive reduction to practice upon an application filed by him in Austria on April 8, 1911. The Examiner of Interferences and the Board of Examiners in Chief agreed that Wahl had established a date of conception of the invention “during the year 1909,” but both tribunals ruled that the evidence failed to show diligence on his part at the time of Braun’s entry into the field; namely, April 8, 1911. The Commissioner, after a careful review of the evidence, agreed with the lower tribunals that Wahl was the first to conceive, and further'ruled that Wahl’s evidence showed diligence just prior to the filing of Braun’s foreign application, and that Wahl’s efforts within a period of two or three weeks resulted in reduction to practice. He therefore awarded priority to Wahl.

Since all the tribunals agreed on’the first question, and as the evidence clearly sustains their finding, we shall confine our discussion to the second.

Max Stahl, superintendent of the Keeley Brewing Company and highly skilled in the art, testified that in the month of March, 1911, Dr. Wahl had spoken to him about his new process, involving the use of lactic acid in the brewing of beer; that about a week later Professor Nilson, in the interests of Wahl, called on him and explained the process, with a view to having it tried. While this px-ocess, according to the witness, “was'against all foxmer teachings,” he finally consented to try it and immediately commenced px’eparations to that end. The *293witness stated: “I told him I would be willing to do it, and would let him know when I had made all preparations for introducing this process. Maybe it was more than a week, but I am sure it was not two weeks until I had all the preparations made and notified Professor Nilson by ’phone, and he brought a half a gallon of lactic-aeid culture, and I started the first mash in his presence.” The witness further stated that he had all the apparatus completed and ready for the installation of the process on April 17, 1911. This date he was enabled to fix by referring to his memorandum book. He further testified that after his reluctance to adopt the process had been overcome by assurances from Dr. Wahl and Professor Nilson, it “took some time to lay out the plans, to put up the tubs, and, after the tubs were finished, to get the steam connectionsthat it was about three weeks after the first interview in March before these preparations were complete, and about two weeks after he had consented to adopt the process. Later the witness produced a receipted bill, dated April 13, 1911, “for inch barrels A. B. angle valves No. 9 and brass A. D. globe valve No. 1,” and stated that these were ordered for the steam-line for the propagating tank, which was used in carrying out the process. Witness stated that this bill “strengthens my statement that the time of three weeks elapsing between the talk I had with Professor Nilson and Dr. Wahl and the propagating of the first liquid, as estimated by me, was a very short estimate.” Witness continued: “I want to be sure that I am right and I don’t want to overestimate myself, so I put it at three weeks.”

In our view the testimony of the above witness, which we have carefully read and partially reviewed, clearly shows activity on the part of Wahl prior to April 8, 1911, resulting, as found by the Commissioner, in reduction to practice. The decision, therefore, is affirmed. Affirmed.