This appeal is from the decision of the Commissioner of Patents, awarding priority of invention to appellee, Land. The decision is based upon a motion by appellee for judgment, on the ground that appellants, having delayed four years after the grant of the patent in issue to Land before presenting the claims and seeking an interference, are gnilty of laches, and therefore estopped from claiming the invention. In the absence of any satisfactory reason for delay, the decision of the Commissioner of Patents is affirmed, on the authority of Chapman v. Wintroath, 252 U. S. 126, 40 S. Ct. 234, 64 L. Ed. 491; In re Fritts, 45 App. D. C. 211; Webster Electric Co. v. Splitdorf Electrical Co., 264 U. S. 463, 44 S. Ct. 342, 68 L. Ed. 792.