it is beaten. Before this hail of death the counter-attack falters, checks, crumbles, and finally breaks, as an ocean roller dissipates itself against a concrete pier in futile spray. Everything used in the assault and in the repulse of the counter-attack—service and automatic rifles, 37-mm. cannon, rifle, gas and hand grenades, machine-guns and trench-mortars, ammunition-carts and voiturettes, mobile charges—is furnished by the Ordnance Department. Reports come in that the enemy is reforming his shattered columns in the shelter of a ridge, preparatory to launching another attack, whereupon the brigade commander orders a machine-gun company to open indirect fire, the rain of bullets mowing down the unseen and now thoroughly demoralized Germans as effectually as though they were advancing in close order across the open. Not only the machine-guns themselves, the tripods on which they are mounted, the ammunition, the belts in which it is contained and the carts in which it is brought up, but the delicate scientific instruments necessary for indirect fire—panoramic sights, clinometers, transits, angle-of-sight instruments, alidades, squares, protractors—are all provided by Army Ordnance. Meanwhile, simultaneously with the conflict on the ground, an aerial battle has been in progress high in the blue, the German airmen, clearly distinguished by the huge black crosses painted on the under side of their planes, attacking the American flyers who are engaged in locating and photographing the enemy positions and in directing the fire of the American guns. To the support of the slow-moving observation and artillery planes speed the fighters of the _escadrilles de chasse_, their stripped machine-guns, synchronized to fire between the blades of their propellers, blazing away at the rate of 1,200 shots a minute. Their machine-gun belts are loaded with tracer, armor-piercing, and incendiary cartridges in rotation, the first permitting the gunner to correct his aim by following the bullet’s flight, the second to pierce the armored tanks of the enemy machines, the third to set them on fire by igniting the leaking petrol or to destroy observation-balloons, while the belts themselves, made of disintegrating steel links, fall apart as they are fired. Giant bombing planes, keeping to the upper levels, head for the German back areas to drop their ugly eggs, ranging in size from the comparatively small bombs used against troops in the open to the 1600-pound monsters which produce craters 100 feet in diameter and 50 feet deep, upon the enemy’s dumps, warehouses, roads, bridges, and railway-stations. Everything save only the airplane itself—the synchronized machine-gun, the disintegrating belt and the special ammunition, the bombs in all their varying sizes, the mechanisms for suspending and releasing the bombs, the sights to determine the exact moment for release, even the ingenious electrical heaters for preventing