A Corps Signal Company exists primarily to provide communication between the headquarters of an army corps and the infantry divisions with their associated divisional field artilleries which constitute a corps. For this purpose it staffs and equips a Corps Headquarters Signal Office, including telephone exchange, telegraph and despatch rider offices; constructs such telegraph and telephone lines to divisions as may be necessary or possible; provides operators at the divisional ends of the lines, and runs and maintains local telephone lines to the different sections of the corps staff, and to the different units of the corps troops. The corps troops—which are those units directly commanded by corps headquarters—though negligible at the beginning of the war, increased enormously with the development of the Heavy Artillery, the Flying Corps, and the rest of the complicated technique of modern position warfare, until finally their communications dwarfed all others. In addition, the Corps Signal Company acts as a repair workshop, and issue store for the signal material and apparatus required by all units and formations within the corps; assists with and correlates their signal arrangements, and provides electric lighting for corps headquarters. To provide for the night and day working and the manning of an advanced headquarters, the Headquarter Section was organized in three reliefs, each under a sergeant superintendent. To increase the number of lines which can be simultaneously run out during a general move, both Air Line and Cable Sections were divided into two detachments, each under a sergeant or corporal. Each air line detachment carried material for five miles of poled line on its lorries, and, after training, became capable of erecting this line at the rate of a mile an hour. Each cable detachment carried nine miles of cable, and learned to lay this out at the gallop when necessary, or at a normal rate of three miles an hour along roads where precautions for the preservation of the line had to be taken.