In this woods we were billeted underground, where we were protected from shell fire. Each detachment was billeted with an equal number of French, and it was from the fourteen French in our detachment that we were to complete our education for the special work for which we were preparing. In other words, we were to learn the practical application from the French of the knowledge that we had learned in the school at Fort St. Menge. Our first experience in actual war work was in an observation tower in this woods. This tower was 65 feet in height. It was cylindrical in form and built of steel about half an inch in thickness. The interior was about five feet in diameter. In the tank (so-called) was a lookout post for observation work. It had small slits on all sides that could be readily opened and shut, through which we were to take our observations. We entered the tower through a trap door in the bottom, and the men working at the post locked the door while they were at their duty. The tower was erected in a thick growth of tall trees, and was well camouflaged. It was securely hidden from Hun eyes, yet gave us a full view of the Hun trenches in that vicinity. It was from this tower that I first saw the enemy, and got my first glimpse of the Hun lines and got my first full view of a modern battlefield. The French outer trench was only one-quarter of a mile from this tower. The German trenches were just a little way beyond those of the French, the distance varying from fifty yards to a quarter of a mile, according to the terrain. With our strong glasses, we could get an excellent view of everything that Fritz did in this part of the line. In this tower the French taught us their secrets of observation in modern warfare. They showed us how to locate German batteries, machine gun nests, railroads, troop movements, supply trains, aerial activity, observation balloons, etc. We paid particular attention to watching how often Hun airplanes arose, where they crossed our lines, whether or not they were fired on by our anti-aircraft guns, the number of Hun planes in the air, the purpose of their flights, etc. It was particularly important to get the point where the German aviators crossed the Allied lines. Their planes followed a system in this so as to try to avoid our anti-aircraft guns. They would cross at a certain point for one or two days, then, believing that if they attempted to cross there again they would meet with a warm reception, they would change the location, thus keeping the Allies guessing all the time. The French remained with us about ten days, during which time we acquired sufficient knowledge to take up the work ourselves, and the American troops then took over this section of the line.