=The Pointing-scale.=--This is made of hard wood, graduated on one side, the unit of the scale being one thousandth of the range, and each division one five hundredth of the range. A brass index-slide moves with friction along the scale and is clamped by a screw when regulated. For reference-marks a brass screw is placed at the end of each cheek of the carriage, and the scale is so arranged that it can be applied to either cheek. The carriage admits of a motion around its pintle of about 15° on either side of the axis of the platform. THE GUNNER'S QUADRANT. [Illustration: FIG. 55.] Used in giving elevation. The arc is 45°, but by applying different sides an elevation of 90° can be given. The least reading is one minute, which is given by the setting of a sliding level on a slightly curved arm. The setting to any given degree is made by moving the arm by hand, which is done by pressing back the head of the arm to release it from engagement with the notches on the interior of the arc, then moving the arm to the required position and allowing the spring to react. AMMUNITION. The full charge of powder is 16 ounces, sphero-hex. (U. F.). The projectiles are those used with the 3.6 gun and have already been described. The charges, required to cover all ranges from 400 to 3350 yards with angles of elevation between 15 and 45 degrees, are four in number. These charges are made up of three cartridges containing 4, 6, 10, and 16 ounces respectively. The =Fuze for Shrapnel= is the Frankford Arsenal point-combination fuze, model 1894, burning 28 seconds and weighing 19.75 ounces. The time-train of this fuze is arranged to be cut at intervals of 1/5 second. The =Fuze for Shell= is fuze M, model 1894. It is identical in construction with fuze C (see page 102), except that a portion of the plunger-spindle is reduced in diameter to lessen the friction of the spring-ring in arming on account of reduced charges. It is distinguished from the C fuze by two grooves across the flat of the base. This fuze is designated for separate transportation, to be assembled with the projectile at or near the firing-ground, and is not to be transported fixed in the projectile. RANGE TABLE FOR 3.6-INCH B. L. MORTAR. Common Shell (Cast Iron). SHELL, filled and fuzed, 20 lbs. Bursting-charge, 14.5 oz.