Encyclopaedia Britannica, 11th Edition, "Baconthorpe" to "Bankruptcy" / Volume 3, Part 1, Slice 2

by Various

Range Table For 6-inch Gun.

Charge	{	weight, 13 lb 4 oz.		Projectile	{	Palliser shot, Shrapnel shell.		Muzzle velocity, 2154 f/s.
		gravimetric density, 55.01/0.504.				Weight, 100lb.		Nature of mounting, pedestal.
		nature, cordite, size 30						Jump, nil.

Remaining Velocity.	To strike an object 10 ft. high range must be known to	Slope of Descent.	5′ elevation or depression alters point of impact.		Elevation.	Range.	Fuse scale for T. and P. middle No. 54 Marks I., II., or III.	50% of rounds should fall in:			Time of Flight.	Penetration into Wrought Iron.
			Range.	Laterally or Vertically				Length.	Breadth.	Height.
f/s.	yds.	1 in	yds.	yds.	° ′	yds.		yds	yds	yds	secs.	in.
2154	..	..	..	0.00	0 0	0	..	..	..	..	0.00	13.6
2122	1145	687	125	0.14	0 4	100	¼	..	0.4	..	0.16	13.4
2091	635	381	125	0.29	0 9	200	¾	..	0.4	..	0.31	13.2
2061	408	245	125	0.43	0 13	300	1	..	0.4	..	0.47	13.0
2032	316	190	125	0.58	0 17	400	1¼	..	0.4	..	0.62	12.8
2003	260	156	125	0.72	0 21	500	1¾	..	0.5	0.2	0.78	12.6
1974	211	127	125	0.87	0 26	600	2	..	0.5	0.2	0.95	12.4
1946	183	110	125	1.01	0 30	700	2¼	..	0.5	0.2	1.11	12.2
1909	163	98	125	1.16	0 34	800	2¾	..	0.5	0.2	1.28	12.0
1883	143	85	125	1.31	0 39	900	3	..	0.6	0.3	1.44	11.8
1857	130	78	125	1.45	0 43	1000	3¼	..	0.6	0.3	1.61	11.6
1830	118	71	125	1.60	0 47	1100	3¾	..	0.6	0.3	1.78	11.4
1803	110	66	125	1.74	0 51	1200	4	..	0.6	0.3	1.95	11.2
1776	101	61	125	1.89	0 55	1300	4½	..	0.7	0.4	2.12	11.0
1749	93	56	125	2.03	0 59	1400	4¾	..	0.7	0.4	2.30	10.8
1722	86	52	125	2.18	1 3	1500	5	..	0.7	0.4	2.47	10.6
1695	80	48	125	2.32	1 7	1600	5½	25	0.8	0.5	2.65	10.5
1669	71	43	125	2.47	1 11	1700	5¾	25	0.9	0.5	2.84	10.3
1642	67	40	100	2.61	1 16	1800	6¼	25	1.0	0.5	3.03	10.1
1616	61	37	100	2.76	1 22	1900	6½	25	1.1	0.6	3.23	9.9
1591	57	34	100	2.91	1 27	2000	7	25	1.2	0.6	3.41	9.7

The last column in the Range Table giving the inches of penetration into wrought iron is calculated from the remaining velocity by an empirical formula, as explained in the article ARMOUR PLATES.

High Angle and Curved Fire.—"High angle fire," as defined officially, "is fire at elevations greater than 15°," and "curved fire is fire from howitzers at all angles of elevation not exceeding 15°." In these cases the curvature of the trajectory becomes considerable, and the formulae employed in direct fire must be modified; the method generally employed is due to Colonel Siacci of the Italian artillery.

Starting with the exact equations of motion in a resisting medium,

(43)	d2x	= -r cos i = -r	dx	,
	dt2		ds

(44)	d2y	= -r sin i - g = -r	dy	- g,
	dt2		ds

and eliminating r,

(45)	dx	d2y	-	dy	d2x	= -g	dx	;
	dt	dt2		dt	dt2		dt