No other British troops, except these three Batteries of ours, ever fought in the Trentino. It was a proud distinction and a very memorable experience. The natural scenery was superb, a series of great mountain ranges, uneven lines of jagged peaks, enclosing deep cut valleys, the lower slopes of the mountains densely wooded, the higher levels bare precipitous rock. The Austrian front line ran along one ridge of peaks and ours along another; between ran a deep valley, all No Man's Land, into which patrols used to climb down at night, often with the aid of ropes. One mountain mass, a continuation of Cima d'Oro, was partly in our possession and partly in theirs, and up there by night among the rocks patrols grappled for the mastery, poised high above the world, and in these struggles men sometimes slipped, or were thrown, to crash to death thousands of feet below in the Val di Ledro. This country was Austrian before the war, though inhabited wholly by Italians, and Italian troops had conquered it with extraordinary feats of endurance and daring in their first great onrush all along their old frontiers in the spring of 1915. But now a big advance here by either side, in the face of carefully prepared opposition, seemed almost inconceivable, except as the result of some wide turning movement, hinging on some point many miles away. The special military problems presented by warfare in such country were numerous and difficult. Our guns had to be dragged into position up a rough mountain track, which at some points was too narrow and at others too weak to allow the passage of a six-inch howitzer without much preliminary blasting and building up. Our first gun to go up took twenty-four hours of continuous labour between the time of starting up the track and the time of arriving in position, a distance of only about two miles of zig-zag. No tractor or other power engine could be used here. The only force available was that of men hauling on drag ropes, and a party of sixty Italian gunners reinforced our men. What may be called the problems of pure gunnery were still more difficult. British Heavy guns had never fired under such conditions before and, for the benefit of such of my readers as may be practical Artillerymen, it may be interesting to remark that for one of our targets the angle of sight, properly so called, worked out at more than twenty degrees, while the map-range elevation was only about fifteen. The devising of an accurate formula for correction of elevation for a large "_dislivello_," as the Italians shortly call it, which in English means a large "difference of level" between a gun and its target, is one of the most intricate problems of theoretical gunnery, or, for that matter, of theoretical mechanics, involving, among other factors, the various shapes and sizes of projectiles, their comparative steadiness during flight, the resistance of the air, and the effect of other atmospheric conditions and of the force of gravity.