This appeal is by the senior party, Cadman, from the decision of the Commissioner of Patents awarding priority of invention to the appellee, Pludson. The invention relates to steering mechanism for four-wheel trailers for auto trucks. It is conceded Hudson was the first to conceive the invention. We think the evidence discloses, as held by the Commissioner and the Board of Examiners, that Cadman reduced to practice about the middle of November, 1916, and that the Hudson reduction occurred a few weeks later. The case turns upon the question of Hudson’s diligence when Cadman entered the field.

The date of conception accorded Cadman, August 31, 1916, is supported by the testimony. Pludson'discloses drawings illustrating the invention, which were made prior to July, 1916. Work was done in checking over these drawings during August, and, on September 29, 1916, Pludson ordered a trailer constructed. A trailer was promptly built in accordance with the drawings. On this showing, which is fully supported by the record, we find no basis for the charge of lack of diligence on the part of Hudson.

The decision of the Commissioner of Patents is affirmed.

Affirmed.

Mr. Justice PIITZ, of the Supreme Court of the District of Columbia, sat in the place of Mr. Justice ROBB in the hearing and determination of this appeal.