C. H. Haswell, Senior Engineer, U. i. Navy, delivered a lecture before the Engineeri,: Institute, oi this city, on the evening of the 25th ult. The subject was the impact of felling bodies, and to present a rule for calcula ting the effect of the falling weight in a pile driver. He illustrated his remarks with experiments.' . The subject is an intricate one. The force of II falling body is its momentum, composed of the weight multiplied into the velocity. Alter the lecture, Mr. Lindsay, the Secretary, made some appropriate remarks ; this institution, we believe, is in a flourishing