Trenches must not be too wide, or they would afford too broad a target to bullets and shells, yet they must be spacious enough to allow comparative freedom of movement to their inmates to pass swiftly from place to place in the event of a sudden attack. They must be roomy enough for the men holding them to live therein with a fair measure of comfort, with places for dug-outs where the men off duty may sleep, and where the officers, who are never off duty, properly speaking, in the trenches, may have their meals and snatch a few hours of slumber between times. There must be safe storage-places for such dangerous wares as ammunition, bombs, fuses, and flares, and specially prepared emplacements for the machine-guns. Sanitation, on which the lives of thousands depend, must also have its special arrangements. [Illustration: _Underwood & Underwood phot._ A CORNER OF A TRENCH WITH A TRAVERSE IN THE EXTREME LEFT--NOTE OFFICER’S GAS HELMET.] The flooring of the trench must be boarded--sometimes in marshy places with two or three layers of planks--against the wet, with “grids” laid across. In the winter not even pumps sufficed to keep the trenches dry. Sandbags, disembowelled by the continual patter of bullets, must be constantly renewed. A stray shell, plumping through the timber and earth roofing of a dug-out, may do damage that will take three days (or rather nights, if the fatigue-party is in view of the enemy by day) to repair. Then the access to the trenches is a question requiring constant attention and unremitting labour. Men in the firing-line roundly declare they would rather be in the front trench than in the area behind the lines. Both sides attempt to embarrass the bringing-up of reliefs and supplies by shelling the roads and communication trenches leading up to the firing-line. Of course, nothing is ever allowed to interfere with the sending-up of reliefs or food, but the shells that crash daily, mostly towards evening, behind the lines claim their toll of life. It is to guard against this promiscuous shelling, against snipers posted in coigns of vantage in the enemy lines, and against spent bullets that come whinneying over from the front (gallant John Gough, most beloved of Generals, was struck and mortally wounded by a stray bullet at a long distance from the firing-line, in a spot that was believed to be entirely safe), that communication trenches are necessary.