In making wire entanglements for the defence of posts any attempt at neatness or regularity is to be avoided; the stakes should be unevenly spaced, and the wire left rather slack with occasional loose loops in it. An entanglement made in this way is harder to pass and to cut than one of the regulation pattern.
Halts at Night.
Unless a halt is to last at least an hour, its duration should not exceed five minutes, otherwise some men will certainly fall asleep, and the operation of waking them causes noise and delay. If a march is to last all night, a halt for a couple of hours, to allow the troops to sleep, is of great benefit, and will diminish but little the total distance covered.
Recognition of Friends at Night.
In repelling a night attack the defenders are always embarrassed by the difficulty of distinguishing between friend and foe, and a previously arranged code of signals is essential if collision between bodies of our own troops are to be prevented. The Russians for this purpose adopted the practice of chanting their National Anthem, and, although the tune of “God save the King” may perhaps be too well known to be safely used, it would be easy to select some simple English song which could not be sung by our enemies.
Knowledge of the Moon and Stars.
An elementary knowledge of the names and positions of the principal constellations and stars is very useful in night work, as without such knowledge there will often be difficulty in pointing out the particular star chosen for the column to march on, and any mistake may have serious consequences. The Manual of Map Reading and Field Sketching states that the lateral movement of a star will not exceed 5° in 20 minutes, and that it is safe to march for about a quarter of an hour on the same star.
If neither the tables given in Appendix III. of the Field Service Pocket Book, nor an Almanac are available, it will be impossible for the ordinary man to calculate accurately the times of the rising and setting of the moon, but a rough knowledge of its phases enables us to estimate approximately the duration of moonlight. When the new moon is first seen it rises in the morning and sets soon after sunset, but as its hours of rising and setting become later each day, by the time it reaches its first quarter the moonlight lasts from sunset to about midnight, and at full moon all night. When the moon begins to wane, and its hour of rising becomes later than the hour of sunset, there is a daily increasing period of darkness between sunset and moon-rise. Consequently, when the moon is growing, moonlight may be expected in the early hours of the night, but after the last quarter not till after midnight.
The number of well educated persons who cannot distinguish between the moon when in the first and last quarter is astonishing, but I have found the old plan of taking a biscuit to represent the moon, and biting pieces out of it to show the different phases, a simple means of explaining the matter to recruits. They soon realise that if, as you look at the biscuit or the moon, a piece is wanting on the left side, the moon is growing; if on the right side, it is waning.