This school is attended by privates from each regiment, who spend four days at their highly explosive studies. Toward the middle of the field, about two hundred yards from one end and about three hundred from the other, was a section of open trench about twenty yards long and some four feet deep. This trench was about the usual three feet in width except in its centre, where for about five feet it was recessed back to a width of some six feet. This was where the French instructor stood and whirled his arms to throw the bombs. A couple of feet to the left of this recess was another recess, covered with a bomb-proof roof of logs and earth. Into this the instructor and his pupil sought refuge from the effects of the bomb explosion. As the explosion really is surprisingly violent and takes place at the longest only five seconds from the time the mechanism of the bomb is started, and at a maximum distance of thirty yards, the instructor and any one in the trench with him have got to be exceedingly spry in running under the bomb-proof in order to beat the bomb. There is, too, the danger of a premature explosion. To make me feel more entirely at my ease, they told me that only a few days ago an officer of explosives brought a Colonel to see one of these demonstrations in another school, behind a different part of the line. As they came to the entrance of the trench the officer politely made way for the Colonel to enter the trench first. As the Colonel did so, the bomb exploded prematurely and killed the Colonel outright. About twenty yards in front of the trench was dug a shallow dummy trench to represent a German target. Some 150 yards further distant was set up a section of wire entanglements. We found the 128 soldiers ranged in line a few yards behind the trench. At its edge I took my place with the Captain of explosives and three or four other officers. The infantrymen lined up two deep behind us. In the open recess in the trench stood the non-commissioned officer of engineers, facing backward toward us. He was the instructor. At the order of the Captain he placed an innocent-looking satchel on the trench edge at his right elbow, plunged a hand into it and briskly plucked out, one after the other, eight different varieties of bombs. Picking them up, one at a time, he gave a terse lecture on the construction and method of operation of each. The bombs were all fully loaded, and the explosion of any one of them would have sent a great many of us well on the way to the cemetery. I noticed in some of the officers, and undoubtedly in myself, a certain tenseness as the engineer nonchalantly illustrated within an inch or two of actuality how a percussion bomb would explode if brought in contact with the ground.