A piquet by night, no matter how well entrenched, has a very limited field of action. Even with most carefully arranged night rests for the men’s rifles its fire effect is small except at close ranges, and to resist attack by relatively larger bodies it must in general keep behind its defences. Hence a well organised scheme of patrols is necessary to supplement the passive opposition which the piquet can offer. The patrols are charged with the duty of bringing news of any advance of the enemy to attack, and, if he is close enough, of spying out his movements on and within his outpost line, of preventing his patrols or scouts penetrating their own line, of watching any localities which are of particular importance and unoccupied by piquets, such, for example, as villages beyond the outpost line which the enemy might try to occupy by night, and, lastly, of keeping up communication between the various bodies of the outposts. The strength of patrols is limited by the necessity of their being able to do this work without making a noise, and a strength of three to eight men is advised. A patrol performs its duty of observation either by going from point to point, or by watching one particular place, when it is called a “standing patrol.” If a piquet posts any group sentries by night, away from the piquet, such groups have just the same work as standing patrols, except that they may be ordered to maintain their position in case of attack as they are near support, whereas patrols would fall back as soon as they had made sure the enemy was advancing, and possibly, if in accordance with their instructions, after treating him to a short burst of rapid fire. An ordinary patrol will also have to halt and listen perhaps for long periods, and so becomes for the nonce a standing patrol. Form up the platoon at the piquet position, and let the commander tell it off into three patrols to practise this duty, disregarding reliefs, all three to be sent out at the same time in different directions, one man in each to be commander. Before they start off, tell them the following, which piquet commanders must see to:— (1) If there is no countersign published for the force, piquet commanders must arrange either a word or a sign by which men may know their own side in the dark. (2) Patrols going out are to tell the nearest sentry which way they are going (I.T., 156 (5)). (3) For patrols a code of signals should be arranged, e.g., a hiss or half-whistle, to call attention, answered by the same to show that the man called has heard it, followed by the signal, whatever it is:—a double hiss for “come up to me,” a click of the tongue for “retire,” but anything will do provided it cannot be clearly heard much further off than the listeners for whom it is intended, and is neither a very common nor a very uncommon sound.