. (a) In the United States army, the a corps of officers and enlisted men consisting of one band and three battalions of engineers commanded by a brigadier general, whose title is Chief of Engineers. It has charge of the construction of fortifications for land and seacoast defense, the improvement of rivers and harbors, the construction of lighthouses, etc., and, in time of war, supervises the engineering operations of the armies in the field. (b) In the United States navy, a corps made up of the engineers, which was amalgamated with the line by act of March 3, 1899. It consisted of assistant and passed assistant engineers, ranking with ensigns and lieutenants, chief engineers, ranking from lieutenant to captain, and engineer in chief, ranking with commodore and having charge of the Bureau of Steam Engineering. [ Webster 1913 Suppl. ]