I saw this mine. It starts in the white chalky soil of some kind of garden outside the château wall. This same white soil nearly proved the undoing of the assailants, for the Germans in the château “spotted” the French operations by the high white piles of clay thrown up from the mine almost level with the top of the wall, and our Allies were forced to explode the mine before the operation was quite complete. However, it did its work well. Two huge craters were made right beneath the wall, the masonry of which was blown apart in great chunks, which were still lying about when I visited the spot. The last German resistance was broken. Vermelles was captured. There will be many Vermelles in this war before the Hun is beaten to the ground. The trench mortar and the bomb have become essential weapons of the war of positions. Both weapons of the past, they seem strangely out of place beside such modern man-slaying instruments as the machine-gun and the magazine-rifle. But they have come in response to the demand of a unique situation because the weapons which military experts believed to represent the last word in progress in their profession no longer sufficed. Handier to manipulate than a field-gun, because much smaller in bulk, of short range, the trench mortar, throwing a heavy bomb filled with high-explosive, might at least blow in a part of a trench which, as I have shown, in the ordinary way is impregnable to direct assault. There are all kinds of trench mortars, from modern specimens to rudimentary kinds of catapults, knocked together by inventive officers or men in their spare time. The French, I believe, have actually used mortars taken from old fortresses of the days of Vauban. Of all the ills attendant on the life of the men in the trenches I know of none more trying to the nerves than these trench mortars. As they are fired at close range from the enemy’s trench, which may be anything from 30 to 300 yards away, one has no warning of their coming. You hear a sudden report mingled with a kind of screech, and the rush of a heavy body through the air, then a deafening explosion, with a spout of earth and clouds of black smoke and a rain of fragments of iron and earth for yards around. The bombs thrown by the big mortars allow you about two seconds--the interval between the impact and the burst--in which to take cover. The small bombs, on the other hand--which our men call “sausages”--burst on impact, without warning.