The identity of the inventions described in the two patents does not appear npon their face, without the assistance of the testimony of experts, and should have been submitted to the jury. Battin v. Taggert, 17 How. 74. Bischoff v. Wethered, 9 Wall. 812. Hill v. Evans, 4 De G., F. & J. 288. Betts v. Menzies, 10 H. L. Cas. 117. New trial ordered.