In the British army, instituted in 1763, consists of about 900 officers and 5000 non-commissioned officers and men, usually recruited from skilled artisans; their duties comprise the undertaking of all engineering operations necessary in the conduct of war, e. g . bridging and mining, road and railway and telegraph construction, building of fortifications, &c.; their term of service is 7 years in the active army and 5 in the reserve, or maybe 3 in the former and 9 in the latter.