Method of obtaining a variable movement of a miniature target, corresponding to rolls of a vessel of from 1 to 10 degrees. A series of 25,000 shots were fired thus, by eight gun pointers, at targets corresponding to the size of a battleship as seen at ranges of 1,500, 3,000, 6,000 and 9,000 yards. Using a sub-caliber rifle rigidly attached to the muzzle of the gun and fired electrically by the firing gear of the big gun. The record shows that under circumstances of average difficulty at sea (say 5 degrees roll and range of 3,500 yards), the gain in accuracy (increase in hits with a given expenditure of ammunition) is about 25 per cent, and the gain in speed of hitting (number of hits in a given time) is 50 per cent, with the two-hand gear as compared with the usual one-hand gear. RANGE FINDER AND PREDICTOR; HOME AND DISTANT STATION INSTRUMENTS. (See page 403.) Continuous readings, by means of automatic indicators, of either the actual or the predicted ranges and azimuths of moving target at every instant and for any distance from 1,000 to 15,000 yards and through an azimuth of 160 degrees, are clearly presented at all times. The ranges are read in scales of 10-yard steps, and the azimuths for each .01 degree are traversed. The corrected ranges for the various guns served by the instruments, either actual or automatically predicted for any interval of time, are constantly communicated to the various guns whose fire is being directed by the observation instrument. ARMOR-PIERCING PROJECTILES, CAPPED AND UNCAPPED. (See page 403.) The projectiles shown are a three-inch capped, a four-inch capped, a five-inch and a six-inch uncapped, eight-inch uncapped and capped, ten-inch uncapped and capped and twelve-inch capped. RANGE FINDER WITH CHART ATTACHMENT. (See page 404.) The chart is drawn on the lower and ground side of a ground glass plate. A pencil point is secured to moving cross-head and marks position of target on ground glass, tracing movement of same thereon. The pillar mounting allows of ready removal of chart attachment when it is not desired to use the same. EIGHTEEN-INCH, THIRTY-CALIBER TORPEDO GUN. (See page 404.) Weight, 134,000 pounds. Length of gun, 528 inches. Weight of projectile, 2,000 pounds. Travel of projectile in bore, 432.4 inches (24.02 calibers). Weight of charge, 310 pounds of smokeless powder. Muzzle velocity, 2,000-foot seconds. Muzzle energy, 55,500-foot tons. Greatest diameter of gun, 45 inches. Its breech mechanism was opened and closed by one man in nine seconds. It was also opened without great effort by a boy twelve years of age. FIRING GEAR FOR GUNS. (See page 405.)