All the tricks of war are being used to check and kill our patrols. In addition to trip-wires attached to explosives, German helmets have been left about with bombs concealed in them so as to explode on being touched, and there are other devices of this kind which are ingenious and devilish. The enemy's snipers and machine-gunners give our men greater trouble, but are being routed out from their hiding-places. There were a lot of them in the ruins of Pusieux, but last night, after sharp fighting and a grim man-hunt among the broken brickwork, the enemy was destroyed in this village, and our line now runs well beyond it to Gommecourt, on the left and down to Irles on the right. The enemy has destroyed Irles church tower, as he has destroyed the church of Achiet-le-Petit, and the famous clock tower of Bapaume, on which we tried to read the time from the high ground westward during the battles of the Somme. This is to get rid of observation which might be useful to us in our advance. Heavy shell-fire has been concentrated by enemy batteries on the village of Irles, and he is also barraging with high explosives upon Serre, Miraumont, Grandcourt, and other places from which he has withdrawn. It is probable that he is using up his reserves of ammunition in the dumps along the line of his retirement. Many of his heavy guns still remain on railway mountings behind Bapaume--we are now less than a mile from that town--and they are doing double duty by quick firing. The latest village to fall into our hands is Thilloy, north of Ligny-Thilloy, and just south of Bapaume, and the enemy is now retiring to Loupart Wood, Achiet-le-Petit, and Bucquoy, strongly defended for the time being by a thick belt of wire. It is enormously interesting to speculate upon this new plan of the German High Command. It is a plan forced upon him by steady pressure of our attacks, which thrust him into bad ground, where the condition of his troops was hideous, but, beyond all, by the fear that our fighting power in the spring might break his armies if they stayed on their old line. Now he is executing with skill, aided by great luck--for the foggy weather is his luck--a manoeuvre designed to shorten his line, thereby increasing his offensive and defensive man-power, and to withdraw in the way that he intends to make it difficult for pursuit, and so to gain time to fall back upon new and stronger lines of defence. * * * * * It is difficult to describe the feelings of our men who go forward to these villages and capture them, and settle down in them for a day or two, unless you have gazed at those places for months through narrow slits in underground chambers, and know that it would be easier to go from life to eternity than cross over the enemy's wire into those strongholds while they are inhabited by men with machine-guns.