One thing that was annoying to our advance was the German "pill boxes" in which machine gunners were placed. These pill boxes were of concrete. They were round and flat, a few square, and took their name because of their resemblance to a pill box. They had slits about six inches wide and eighteen inches long in the concrete through which the Huns fired their machine guns at our troops. Our most effective weapon against these pill boxes was our one pounders. They fired a small shell directly at the box and continued to fire until they got the range of the slit. The shells would then penetrate the slit and hit the other side of the box, exploding when they did so, and killing or wounding the occupants. Once the range was obtained, our gunners kept pouring in these shells until there was no longer any fear that the Fritz soldiers in that box would harm any more Americans. Our boys put many of these pill boxes out of commission with big loss to the enemy. They made duty in a pill box certain death for the Huns when any Americans were around. We spent a rather restless night after our first day's advance. Though we had marched many miles and were mentally and physically fatigued, it was not easy to sleep. We were in constant danger of counter attack and of being shelled by the enemy, and the sensation was not pleasant. Early in the morning of September 13th, the second day of the drive, we advanced again in the gray of the early dawn. It was between 8 and 9 o'clock on this morning that I saw a great aerial fight in which probably thirty-five and perhaps forty machines participated. We had advanced so far the first day that the Germans sent their aircraft out in numbers on the second day to look at the territory that had been lost. Our men were ready for them. It was the most thrilling sight I ever witnessed, and I cannot imagine anything more sensational. At first these machines were very high in the air, perhaps ten thousand feet, for they were mere specks in the sky to the natural vision. It was wonderful to see them manoeuvering for positions of advantage. They twisted, turned, looped and dove. At times two or three would be very close together and then again they would separate. Little white puffs of smoke told the tale that the machine guns were in action. They reminded me of bees swarming, as they buzzed and circled around each other in the air. As they fought they descended, coming nearer to earth and thus plainer to our vision. Suddenly one dropped out of the ranks, a struck machine. We knew it was permanently out of commission the minute it started to fall, for it dropped like a dead bird. It was a Hun machine and it dropped close to where I was located, so close in fact that within a few minutes I was inspecting it and taking small souvenirs to send home from its collapsed wings. Then another dropped, but it fell far from where we were located and its descent was so swift that we could not see its insignia and were unable to tell