left is by next day non-existent--even the airmen looking down on it from above in the mists of the grey dawn can scarcely tell where it was. Then some community of ants sets to work and the line begins to show again. Again it is obliterated, until a stage comes when the German decides that it is not worth while digging it out. He has other lines, and he turns his energy on to them. The result of all this is that areas of ground in the hot corners of battles like that of the Somme and Verdun, and especially disputed hill summits such as the Mort Homme or this Pozieres Ridge, become simply a desert of shell craters. A few days back, going to a portion of the line which had considerably altered since I was there, I went by a trench which was marked on the map. It was a good trench, but it did not seem to have been greatly used of late, which was rather surprising. "You won't find it quite so good all the way," said a friend who was coming down. Presently, and quite suddenly, the trench shallowed. The sides which had been clean cut were tumbled in. The fallen earth blocked the passage, and the journey became a switchback over tumbled rubbish and into the trench again. Someone had before been living in the trench, for there were tools in it and bits of soldiers' gear. Here and there a shattered rifle stuck out of the terra-cotta soil. The trench shallowed still further. There had been little hastily scraped dug-outs in the sides of it. They were more than three parts filled with earth; but in them, every now and again, there showed a patch of muddy grey cloth above the debris. It was part of the uniform of a German soldier buried by the shell that killed him. It must have been an old German trench taken by our men some weeks before. It can scarcely have been visited since, for its garrison lay there just as the shells had buried them. Probably it had been found too broken for use and had been almost forgotten. The trench led on through these relics of battle until even they were lost altogether; and it came out into a region where it was really a puzzle to say what was trench and what was not. Around one stretched a desert of shell craters--hole bordering upon hole so that there was no space at all between them. Each hole was circular like the ring of earth at the mouth of an ants' nest several thousand times magnified, and they stretched away like the waves of the sea. Far to the left was a bare, brown hill-side. In front, and to the right, billows of red shell-holes rose to the sharp-cut, white skyline a hundred yards away. You feel as a man must feel in a very small boat lost in a very wide ocean. In the trough of a shell-hole your horizon was the edges of the crater on a level with your head. When you wandered over from that shell-hole into the next you came suddenly into view of a wide stretch of country all apparently exactly the same as that through which you were plunging. The green land of France lay behind you in the distance. But the rest of the landscape was an ocean of red craters. In one part of it, just over the near horizon, there protruded the shattered dry