patrols), will detail the various duties, and will make the necessary sanitary arrangements. His sentries should be posted as expeditiously as possible, and his patrols sent out at once. The number of patrols to be furnished depends upon the nature of the country, and as each patrol requires two reliefs, their number should not be greater than circumstances demand. The duties of infantry patrols are to search the ground and buildings, etc., for about 2,000 yards in front of the sentry line, to find out whether the enemy is there or not, and if the enemy is found to be close at hand to watch his movements and report frequently. The number of Sentry Groups depends upon the nature of the country and the height of the line of observation, but between them the groups must be answerable for the whole of the ground in front of their Piquet (up to its junction on the left and right with neighbouring Piquets). A Sentry Group consists of 6 men under a N.C.O. (2 on duty and 4 off), and groups are usually posted not more than 400 yards from their Piquet, and hold their ground unless ordered to withdraw. If invisible from their Piquet a connecting sentry should be posted by the Piquet commander. Sentry Groups required for night dispositions only will not be posted until after dark. In order to prevent the men of the Piquet being unnecessarily disturbed at night the N.C.O. and {137} men of each relief must be made to bivouac together, apart from other reliefs and from the remainder of the Piquet. A sentry will always be posted over the Piquet, to watch the Sentry Groups and connecting sentries, and ready to alarm the Piquet at any moment of need. Patrols consist as a rule of a complete unit of 3 to 8 men under a N.C.O., and should be formed of men trained as scouts, although it will sometimes be possible to use only single scouts for this purpose, owing to the vigilance of the enemy. Standing patrols may also have to be furnished, if required to watch some special point, particularly at night, or at the junction of roads converging towards the Piquet line, at cross roads, etc., when they are out of sight of the sentries. The Piquet will stand to arms, every man in his allotted place, an hour before dawn, and will remain alert until the patrols (which are invariably sent out about that time) have reported absence of movement by the enemy. Outposts are generally relieved at dawn, so that the force is doubled at the hour of danger. All troops in the Outpost Line must entrench themselves, if posted as sentries, or in the Piquet or Support positions, and must be ready at any moment to resist a sudden attack. A detachment of Royal Engineers will usually be available to superintend the consolidation of the main position.