delivered the opinion of the Court:

From a decision of the Patent Office awarding priority of invention to James JI. Nesbitt and John C. Lauritzen as joint inventors of a collapsible meial core composed of sections upon which a pneumatic; tire may be molded, John Yemiker appeals. The counts of the interference are:

“1. A core of the character described comprising a plurality of separable sections having inwardly extending portions provided with grooves which, in the assembled condition of the sections, provide an annular channel, and an annular wedge ring insertible in said channel, and adapted to be held therein by friction.

“2. A core adapted to have tire shoes and casings built and vulcanized thereon, said core including an annulus comprising an outer main body and an inwardly extending flange having an enlarged marginal portion providing shoulders perpendicular to the faces of the flange, said annulus being formed of a plurality of sections and said enlarged portion of the flange having a channel therein opening out through one of the side faces of the same and also being provided with spaced apart openings leading from the bottom wall of said channel through the opposite face of said enlarged portion and a ring adapted to be forced into said channel as and for the purpose described.”

John Yemiker is the junior party; therefore he has the burden of establishing his claim. Nicoll v. Hoey, ante, p. 245.

He asserts that the appellees are not joint inventors, because they failed to show when and where they conceived the invention. Nesbitt testified that they were joint inventors, and the witness Ilerdman said that the invention was explained to him by both of them. Against this there is no evidence. Under the rule in Lemp v. Randall, 33 App. D. C. 430, Yemiker’s contention must be rejected.

*252Yemiker claims that he conceived the invention in 1912. The Commissioner’s analysis of the testimony on this point makes it clear* that he did not. But even if he did, he lacked diligence in reducing the invention to practice. ITis application for a patent was not filed until January, 1915, more than two years after his alleged conception; and he made no reduction to practice prior to that, unless the production of a core by the Williams Foundry and Machine Company under the direction of Nesbitt in January, 1913, constitutes such a reduction. He claims that it does, and bases his argument upon the assertion that he had revealed the invention to Nesbitt before the core was manufactured, and that the reduction to practice resulting from its manufacture inured to his, Yemiker’s, benefit. Perhaps this would be so if he had disclosed his in\ onticn to Nesbitt, but he had not.

Nesbitt, Lauritzen, and Yemiker were employees of the Foundry & Machine Company. Yemiker admits that the core was made under Nesbitt’s direction, but contends that sometime before he had explained to Nesbitt how he, Yemiker, “was going to strengthen the core with a ring taper on one side straight on the other in order to draw sections together,” and at the same time made and handed to Nesbitt a pencil sketch of the invention. In this he has no corroboration. Nesbitt denies it, but admits that he had a conversation with Yemiker about the time mentioned, in which thei;,latter told him of “a core with wedges, and a ring fastened on same, square, but not to fit tight in cavity.” This answers the description of a structure covered by a patent issued to Yemiker on an application filed in the.previous August. It does not describe a tapered ring, which constitutes the chief feature of the invention under consideration. The admission fails to embrace the issue. With the admission out of the way, Yemiker’s claim of disclosure to Nesbitt is left without sufficient support.

Moreover, the Foundry & Machine Company built and sold after January, 1913, a number of cores embodying the invention. Yemiker was aware of' this. When asked if he made any claim to the company that the core was his invention he *253answered that he told the foreman that he “did not think very much of people that would take an idea away from another man.” Hut the foreman denies this. However that may be, Yemiker did nothing beyond this to protect his interests until he filed his application, nearly two years afterwards. In the meantime, on March 6, less than two months after the first core was built under Nesbitt’s direction, Nesbitt and Lauritzen filed tbeir application for a patent. It is not believed that if Yemiker at that time regarded himself as the inventor he would have remained silent and inactive so long. There are many other circumstances tending to show that he did not make a disclosure to Nesbitt and hence that the manufacture of the core in January was not a reduction to practico of Yemiker’s invention. They are dwelt upon in the respective opinions of the Examiner of Interferences and the First Assistant Commissioner, and it Avould serve no useful purpose for us to set them forth her..

The Examiners in Chief found for the appellant. As avc read their opinion, it turns upon the construction of count 2., They held that this count does not call for a taper on the ring, and that Yemiker’s disclosure to Nesbitt, which is admitted by the latter, satisfies the terms of this count. In this we think they have erred. We agreed with the Assistant Commissioner “tha1 count 2, like count 1, must he construed as limited to a tapered ring.” Yemiker seems to concur in this, albeit bis statement in that regard is not very clear; for he says in his brief that while “count 2 does not call for a tapered ring in a positive way, however, a ring adapted to be forced into said channel found in count 2 might imply the condition, and not the positive element.” Construing count 2 as calling for a tapered ring, the admission of Nesbitt that Yemiker revealed to him a structure described in a patent issued to Yemiker which does not reveal such a ring becomes immaterial, and the ground upon Avbich the examiners based their opinion disappears.

We are of opinion that the First Assistant Commissioner Avas right, and, in consequence, his decision awarding priority to Nesbitt and Lauritzen is affirmed. Affirmed.