In order to maintain the signallers of a unit in full practice and efficiency, the men are excused from all ordinary parades for a certain part of the year; during manœuvres they are attached to the headquarters staff of their unit and carry on their work as signallers, not as ordinary duty-men. The wagging of flags is only a part of their duty, for they have to learn the mechanism and use of the heliograph, since, when sunlight permits of its use, this instrument can be employed for the transmission of messages to a far greater distance than is possible even with large flags. Lamps for signalling by night are operated by a button which alternately obscures and exhibits the light of a lamp placed behind a concentrating lens. The practised signaller is as efficient in the use of flags, lamps, and heliograph as is the post-office operator in the use of the ordinary telegraph instrument, though the exigencies of field service render military signalling a considerably slower business than ordinary wire telegraphy. Another course of instruction which carries with it a certain amount of exemption from duty in the infantry is that of scout. The practised scout is capable of plotting a way across country at night, marching by the compass or by the stars, making a watch serve as a compass, military map-reading--which is not as simple a matter as might be supposed--and of making sketches in conventional military signs of areas of ground, natural defensive positions, and all points likely to be of interest and advantage from a military point of view. The work of the signaller has been going on for many years, but the training of scouts is a movement which has come about and developed almost entirely during the last twelve years, which, as the Army reckons time, is but a very short period. It may be anticipated that the practice of scouting and the training of scouts will develop considerably as time goes on. Needless to say, the orderly-man is excused all parades during his day of duty as such. Only in exceptional circumstances are cooks taken for parades, and such men as the regimental shoemaker, the armourer and his assistants, and other men employed in various capacities, attend the regular duty parades very seldom. On field days occasionally, and also on certain commanding-officers’ drill parades, the orders of the day announce that the battalion will parade “as strong as possible.” This means a general sweep up and turning out of men employed in various ways and excused from parades as a rule, and their unhandiness owing to lack of practice sometimes results in their being relieved from their posts and returned to duty, while frequently it involves their doing extra drills in addition to their regular work.