The groundwork of practical naval gunnery; a study of the principles and practice of exterior ballistics, as applied to naval gunnery, and of the computation and use of ballistic and range tables . the arbitrary deflection scale for sights, whichhas recently been adopted for service use. impact. RANGE TABLES; THEIR COMPUTATION AND USE 197 326. If we were shooting at 10,000 yards on the sight bar, with the same gun,and gave a spot of up 200, this woukl raise the position of the point of impact on 28x300 the target screen, or rather in the vertical plane through it, a distance of ~ ^an^^ — ^^fee
The groundwork of practical naval gunnery; a study of the principles and practice of exterior ballistics, as applied to naval gunnery, and of the computation and use of ballistic and range tables . the arbitrary deflection scale for sights, whichhas recently been adopted for service use. impact. RANGE TABLES; THEIR COMPUTATION AND USE 197 326. If we were shooting at 10,000 yards on the sight bar, with the same gun,and gave a spot of up 200, this woukl raise the position of the point of impact on 28x300 the target screen, or rather in the vertical plane through it, a distance of ~ ^an^^ — ^^feet. 327. In all wind and speed problems, draw roughly separate diagrams for in each diiigram a-lieavy line in the proper direction, to show target and Avind. the line of fire. For the gun and for the target, put the ship at the center, headingcorrectly, and draw a dotted line in the proper direction for the course of the gun orthe target. For the wind draw a dotted line through the center with an arrow point-ing in the direction towards which the wind is blowing. Find the angle, less thani)0°, between course of gun or target or direction of wind, and line of fine. The cosine / /. / A^O^/aTX £7/ T^r^e/ Figure 29 of that angle represents change in range, and the sine, change in deflection. We arenow in a position to proceed to the solution of some every-day practical problems bythe use of the range tables, and for the first one we will take a ship steaming southwestat 18 knots, which wishes to fire a 12 gun (7 = 2900 f. s., w = 8r0 pounds, c = )at another ship that is 8000 yards distant and bears 30° off the port bow of the firingship at the moment of firing. The target ship is steaming west at 22 knots, and thereal wind is blowing from the south at 20 knots. The barometer is at and thethermometer at 20° F. The temperature of the powder is 70° F. Drying out ofvolatiles has raised the initial velocity of 25 f. s., and dampness of powder has reducedit 10 f.
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Keywords: ., bookcentury1900, bookdecade1910, booksubjectballistics, bookyear1
