While guard duty is kept as light as possible in mounted branches of the service, it is allowed to assume large proportions in the infantry. In a cavalry regiment, the “main guard,” which mounts duty for twenty-four hours and has charge of the regimental guard-room and prisoners confined therein, is composed at the most of a corporal and three men, but in the infantry the main guard of a battalion consists of a sergeant, a corporal or lance-corporal, and six men, providing three reliefs of two sentries apiece. Guard duty is done in “review order.” That is to say, the men dress up in their best clothes, with the last possible polish on metal-work and the best possible pipeclay on all belts and equipment that permit of it; and the inspection to which the guard is submitted before taking over its duties is the most searching form of inspection which the soldier has to undergo after he has been dismissed from recruits’ training. The men of the guard do turns of two hours sentry-go apiece, and then get four hours’ rest, except in very inclement weather, when the periods are reduced to one hour of duty and two hours of rest. Experience has placed it beyond doubt that the “two hours on and four hours off” is the best way of doing duty in reliefs; it imposes less strain on the men, who have to keep up their duty for a day and a night, than any other form in which it could be arranged. Certain men in infantry units--and in fact in all units--are excused from the regular routine of duty in order to fill special posts. Noteworthy among these are the “flag-waggers” or regimental signallers, a body of men maintained at a certain strength for the purpose of signalling messages with flags, heliograph, or lamps, by means of the Morse telegraphic code, and also with flags at short distances by semaphore. Bearing in mind the average education among the rank and file, it is remarkable with what facility men learn the use of the Morse code. Against this must be set the fact that only selected men are employed as signallers; these are taught the alphabet, and the various signs employed for special purposes, by being grouped in squads, and, after their preliminary instruction is completed, they are sent out to various points from which they send messages to each other, under conditions approximating as nearly as possible to those which obtain on active service.