3-008-363 - The Print Collector/Heritage Images

The War in America: a night alarm in the Federal camp - signalling from the right bank of the Potomac to head-quarters at Washington, from a sketch by our special artist, 1862. 'Frequently there are alarms in the Federal camp on the Potomac at night caused by the driving in of the pickets and the appearance in force of the Confederates at different points of the Union lines. On these occasions it is necessary to communicate with the Commander-in-Chief, and to do this expeditiously a new system of signals has been introduced into the Federal army. By day messages are sent from one division to another by the use of differently-coloured flags, thus doing away with the necessity of dispatching mounted troopers with written orders; and by night lamp-torches take their place with the same effect. These signals can be used with an army in motion, the corps attached to the different brigades occupying as they move all elevations or lofty buildings on their route. At the signalman's feet lies a large brass lamp, which is the axis around which the motive light forms its curves - each curve, according to the direction which it takes, signifying a number, the meaning of which number being known only to the officer commanding each corps'. From "Illustrated London News", 1862.