The French design for the telescopic sight for the 37-millimeter gun used on the tanks was also adopted by the Army. Here again difficulty was experienced in manufacture, but excellent progress was made especially by one firm (Burke & James of Chicago, Ill.), and the output in adequate quantities was assured for 1919. The French collimator sight for the 75-millimeter gun presented difficulties to the manufacturer, especially in the optical parts. These were, however, overcome by the Globe Optical Co., who furnished the optics to the Electric Auto-Lite Corporation and to the Standard Thermometer Co. of Boston, with the result that at the time of the signing of the armistice the production of these sights was progressing well. Periscopes from 20 inches to nearly 20 feet in length were produced in quantity. These periscopes enabled the men in the front-line trenches to look over the top with comparative safety. The long periscopes were used in deep-shelter trenches and bomb proofs. The production of the short-base periscopes and also of the battery commanders' periscopes by the Wollensak Optical Co., Rochester, N. Y., and of the 3-meter and 6-meter periscope by the Andrew J. Lloyd Co. of Boston, Mass., was progressing at such a rate that the needs of the Army for 1919 would be met on time. At the outbreak of the war the policy followed by the Ordnance Department was to place orders for standard fire-control apparatus, such as range finders of different base lengths, battery commander telescopes, aiming circles, panoramic sights, musket sights, and prismatic compasses with firms of established reputation and experience. The result was that when requests from the Army in France came for instruments of new design, new sources of manufacture had to be sought out and these organizations educated in the methods of precision optics. Such a procedure necessarily caused delay, but it was the only course of action left. Wherever possible part of the total contract was awarded to an experienced manufacturer, so that some production was assured. [Illustration: PANORAMIC SIGHT.] [Illustration: BATTERY COMMANDER'S TELESCOPE.] [Illustration: BATTERY COMMANDER'S PERISCOPE.] [Illustration: AIMING CIRCLE.] [Illustration: BRACKET FUSE SETTER, MODEL OF 1916.] [Illustration: RANGE FINDER.] [Illustration: FRENCH QUADRANT SIGHT WITH AMERICAN PANORAMIC SIGHT.] [Illustration: SIGHT FOR 75-MILLIMETER FIELD GUN.]