range and power anything which the Germans had at Metz or the British at Gibraltar, they are extremely mobile, any one of them being able to drop its load of high explosive far behind the enemy’s lines, “pull stakes,” and be miles away before the enemy could get its range. [Illustration: A 12-INCH SEACOAST MORTAR ON A RAILWAY MOUNT.] [Illustration: 6-INCH SEACOAST RIFLES TAKEN FROM COAST FORTIFICATIONS AND MOUNTED FOR FIELD USE IN FRANCE.] Speaking of the range of artillery, some truly amazing results in this field were achieved by Major Forest Ray Moulton, one of America’s foremost mathematicians, who was professor of astronomy in the University of Chicago before he was given a commission in the Engineering Division of Ordnance and turned his knowledge of ballistics to military account. One usually thinks of a professor of astronomy as a highly impractical person whose mind is absorbed in comets, meteors, and stars, yet no individual in the armies of the United States did as much as Doctor Moulton toward perfecting devices for killing Germans at long range. Here is a sample of his achievements. As the result of a series of abstruse calculations he made a change in the shape of the copper driving-band on the 6-inch shell, whereby, _without adding to the powder charge and with no modification whatever in the gun, he increased its range two and a half miles_. What is even more remarkable and important, he so reduced the variation between successive shots that a given number of shell will fall into one-eighth the area formerly covered by their dispersion. Had the war continued a year or so longer, there is no saying where Doctor Moulton’s ballistic discoveries would have led. It was evidently of one of the shell designed by him that the negro soldier remarked: “Ah could staht runnin’ at brekfus’-time an’ that theah shell ’ud git me jes’ when Ah got home foah suppah.” Whereupon his companion exclaimed scornfully: “All one of dem shells wants is jes’ yo’ address, niggah—jes’ yo’ address.” * * * * *