[1,2] Judge Hunt has made a clear statement of the improvements covered by the claims in issue and a careful analysis of the various defenses and alleged anticipations urged by the appellant. We agree with him except as to claim 6 of No. 759,389. This claim as originally inserted was as follows: “A caisson having a cutting edge of masonry.” After the trial, but prior to the final submission of the case, the plaintiff filed a disclaimer which limited this claim to concrete, so that it read: “A caisson having a cutting edge of concrete.” It is not contended that the alleged infringing structure has a cutting edge of concrete. All that counsel for the plaintiff asserts in this particular is that “the cutting edge of the Walker-Lispenard caissons is backed solidly by concrete and its face half concrete and half iron.” In other words, the contention is that a cutting edge half iron and half concrete is a cutting edge of concrete. We are unable to agree with this contention, as the claim is expressly limited to a cutting edge of concrete.

The decree is affirmed, with costs, but with half co§,ts only as to patent No. 759,389.