Page:EB1911 - Volume 20.djvu/239

results given by various formulas. These often vary considerably, so in order that a direct comparison in the tables may be made, this value is obtained for wrought iron plate only, using Tresidder’s formula, which is one of the most trustworthy. The equivalent thickness of Krupp cemented steel armour can be obtained immediately by dividing the tabulated value for wrought iron by a “factor of effect” of 2·3 to 2·4 for uncapped armour piercing shot, and about 2·0 for capped armour piercing shell. These factors are dependent on the nature of the projectile and must therefore be taken as approximate.

Tables VIII.-XXII. are obtained from trustworthy sources, but as great secrecy is now observed in many countries there may be a few inaccuracies; in some cases the whole of the data are not available.

Table IX. — French Naval Ordnance, 1910.

Official Designation of Gun.	Calibre.	Weight of Gun.	Weight of Charge.	Weight of Projectile.	Muzzle Velocity.	Muzzle Energy.	Perforation of Wrought Iron.	Rate of firing Rounds.	Propellant.
	In.	Tons.	℔.	℔.	Ft.-Secs.	Ft.-Tons.	In.	Per Minute.
305 mm.	12·01	..	..	750	2870	42,890	46·0	1·5	Smokeless B. Powder
274 ,,	10·8	34·5	..	562	2650	27,186	38·8	1·5
240 ,,	9·45	23·6	..	375	2870	21,445	37·0	2	,,
194 ,,	7·64	12·5	..	190	2870	10,890	29·0	2	,,
164·7 ,,	6·46	8·5	..	115	3000	7,185	26·3	4	,,
Q .F. Guns—									,,
164·7 mm.	6·46	8·1	..	115	2870	6,568	24·5	5	,,
140 ,,	5·44	4·13	..	66	2625	3,153	20·0	6	,,
100 ,,	3·94	..	..	31	2395	1,232	12·4	6	,,
75 ,,	2·9	..	..	14	3116	943	14·5	12	,,
65 ,,	2·57	..	..	8·8	2871	503	10·8	12	,,
47 ,,	1·85	..	..	3·3	2871	188	7·9	15	,,

Table X.—German Naval Ordnance.

Official Designation of Gun.	Calibre.	Weight of Gun.	Weight of Charge.	Weight of Projectile.	Muzzle Velocity.	Muzzle Energy.	Perforation of Wrought Iron.	Rate of firing Rounds.	Propellant.
Q.F. Guns—	In.	Tons.	℔.	℔.	Ft.-Secs.	Ft.-Tons.	In.	Per Minute.	Nitro- Glycerine powder
28 cm.	11·02	33·3	..	529	2854	29,878	40·2	1
24 ,,	9·45	25·4	88·2	309	2740	16,086	31·0	11/2
21 ,,	8·2	15·75	49·5	242	2526	10,707	26·1	3	,,
17 ,,	6·7	7·8	43·1	132	2887	7,629	26·1	5	,,
15 ,,	5·9	4·73	19·83	88	2461	3,696	18·0	7	,,
10·5 ,,	4·13	1·645	7·27	38·35	2297	1,403	12·75	8	,,
8·8 ,,	3·42	1·34	4·85	23·6	2789	1,273	14·7	10	,,
5  ,,	1·97	0·236	0·66	3·86	2165	125	5·4	11	,,

Note. — It is stated that the new German 28 cm. 50 calibre naval gun weighing 43·9 tons fires, with a charge of 291 ℔,
a projectile of 760 ℔ with a velocity of 2871 f.s.

Table XI.—Italian Naval Ordnance, 1910.

Official Designation of Gun.	Calibre.	Weight of Gun.	Weight of Charge.	Weight of Projectile.	Muzzle Velocity.	Muzzle Energy.	Perforation of Wrought Iron.	Rate of firing Rounds.	Propellant.
	In.	Tons.	℔.	℔.	Ft.-Secs.	Ft.-Tons.	In.	Per Minute.
343 mm.	13·5	67·9	187·2	1215	2067	36,050	34·0	..	Strip Ballistite
305 ,,	12	51	231·5	850	2580	39,220	42·0	..	,,
254 ,,	10	30	85	450	2461	19,000	31·0	..	,,
203 ,,	8	19	57	250	2526	11,060	27·0	..	,,
152 ,,	6	5·7	17·6	100	2296	3,655	17·0	..	,,
120 ,,	4·72	2·1	5·5	45	2116	1,397	11·4	..	,,
76 ,,	3·0	0·6	2·17	12·5	2296	457	8·5	..	,,
57 ,,	2·24	0·4	1·05	6	2198	201	6·3	..	,,
47 ,,	1·81	0·25	0·67	3·3	2330	124	5·8	..	,,

Table XII.—Russian Naval Ordnance, 1910.

Official Designation of Gun.	Calibre.	Weight of Gun.	Weight of Charge.	Weight of Projectile.	Muzzle Velocity.	Muzzle Energy.	Perforation of Wrought Iron.	Rate of firing Rounds.	Propellant.
	In.	Tons.	℔.	℔.	Ft.-Secs.	Ft.-Tons.	In.	Per Minute.	${\Big \{}$Nitro- Cellulose
12 in.	12	59	..	720	2600	33,730	39·0	..
10  ,,	10	32	..	488	2550	22,003	34·0	..	,,
8 ,,	8	14	87	188	2950	11,345	29·5	..	,,
6 ,,	6	6·28	50·6	91·5	2118	2,849	14·4	..	,,
9 pr.	4·2	0·87	4·88	27·75	1226	289	4·2	..	,,
4 ,,	3·43	0·45	3·1	15·0	1451	219	4·6	..	,,
Q.F. Guns—
6 in.	6	5·75	28	91·5	2502	3,970	18·5	..	,,
4·7 ,,	4·72	2·95	15·4	45·0	2502	1,953	14·6	..	,,
2·9 ,,	..	0·87	3·53	10·8	2700	546	10·3	..	,,
1·81 ,,	1·81	0·323	..	3·3	2003	91·8	4·6	..	,,