As a rule, when the assembly is complete there is too much congestion for officers and N.C.O.'s to move about amongst their men. Then walking along the trench is like passing to one's seat in the centre of the stalls after the curtain has gone up; in the darkness the floor seems carpeted with feet, and one stumbles along what appears to be a narrow passage with its walls bristling with projecting knees. The time spent in the assembly trenches hangs heavily. The throats of the men get dry, partly because they are told they must not cough, and partly perhaps for other reasons. In these circumstances men have a peculiar desire to cough, just as a congregation has towards the end of a long and tedious sermon. If one man begins, the rest take it up. The noise thus made appears deafening. To obviate this, petrol tins of water and tea in hot food-containers have been dumped about the assembly positions, so that men may from time to time moisten their mouths and throats. Further, a tot of rum is served to all. Rum played a great part in the war. It produces a marvellous and immediate effect, dispelling depression, creating warmth, and stimulating the morale. Even the staunchest teetotallers will drink rum with avidity in the assembly trenches. There is a further disquieting thought which occurs during this period, particularly to commanders. Will the enemy discover that our foremost trenches are packed solid with humanity, that almost all our eggs are in one basket? Has that infernal listening machine overheard details of the day and hour carelessly spoken over the telephone, in spite of the many orders on the subject? If he discovers we are here, he will produce what he pleases to call annihilating fire, in which he concentrates his guns and trench-mortars on our assembly position. When he has been successful in doing this, the results have been indescribable. Each shell that falls into the trench bursts in the midst of a closely-packed group of men. The members of the various headquarters therefore anxiously listen for any signs of an enemy bombardment, and are only relieved of their anxiety when the arrival of zero hour is denoted by the opening of the British barrage. The reserve troops of the two leading brigades were safely accommodated in deep dug-outs, secure from any bombardment which the enemy might open in reply to the attack. The 154th Brigade in reserve lay at Mailly-Maillet Wood, out of the range of field howitzers, their headquarters being at the Café Jourdain.