The original distinction between military and civil engineering has gradually lost its force, in no small measure because of the practical interchange of military and civil engineers on governmental works that are wholly civil in nature. The record of the graduates of West Point in river and harbor improvement, culminating perhaps in the construction of the Panama Canal, is evidence of this tendency. In recent months, however, any line of separation between civil and military engineers has been wholly lost sight of by reason of the military contribution of civilian engineers to the military program, which has been so largely an engineering program. How great and varied that contribution has been will doubtless be set forth in some presidential address before one of the great engineering societies, yet this meeting of the Geological Society of America is an opportune time for mention of one phase of this progress of engineering. . . .