American artillery may be roughly divided into four classes: light, medium, heavy, and railway. The light artillery consists of two types: the little, hard-hitting 37-mm. infantry-accompanying cannon, operated by two men, primarily designed for knocking out “pill-boxes” and machine-gun nests and, with a shortened barrel, for use in tanks, and the 75-mm. field-gun, an American adaptation of the famous French _soixante-quinze_, which, according to the admission of the French themselves, it in several respects excelled. Three types of weapons are included in the medium-calibre class: the 4.7-inch field-gun, which we had adopted and had manufactured in small quantities prior to our entrance into the war; the 155-mm. G. P. F. (_Grand Puissance Filloux_), really a big brother of the “seventy-five,” with correspondingly increased power and range, designed for interdicting crossroads and harassing the enemy’s middle areas, and the 155-mm. howitzer, which with its plunging fire is admirably adapted for trench and dugout demolition. In mobile heavy artillery we have the 8-inch and 9.2-inch howitzers, likewise designed primarily for demolition purposes. And, finally, the great 8, 10, 12, 14, and 16 inch pieces—guns, howitzers, and mortars—mounted on and fired from specially designed railway-trucks suited to the French road-beds—for incessant pounding of the depots, dumps, headquarters, and railways far behind the enemy’s lines. In addition to the above there are, of course, the various types of antiaircraft artillery, mainly of 75-mm. calibre, and the trench-mortars, ranging in size from the 3-inch Stokes, light enough to go over the top with the first wave of an attack and simple enough to be fired when supported only by the knees of a squatting soldier, up to the 240-mm. trench-mortar of position, whose great shell can blow the stoutest concrete fortification to smithereens. We also had in use at various times small numbers of miscellaneous calibres and types, but, as the result of the policy of reducing the number of types in order to simplify the problem of ammunition supply, our artillery had become fairly well standardized by the closing months of the war.