_______________ ______________________
_________
__________________________________
__________
13'
10'
c.
8'
T = -25 V 3R
Cubic content
576 molesworth’s pocket-book
Gunnery, &c. (by Capt. Bridges, R.A.)—continued.
Ranges, &c., of Mobtabs.
VELOCITY. .
R = Range in yards. T = Time of flight.
c = Charge in ozs.
R+ i R
mortar------— = c.
orf
R + 160
” 50
ll+£
or —______- if R exceeds 1350 yards.
R + 20
mortar ——— = c.
bb
Memoranda on Gunpowder (Service).
Composition:—75 saltpetre, 10 sulphur, 15 charcoal.
Average specific gravity of the various sorts used in the
Engineer Service is to water as ‘8988 : 1.
Average weight per cubic foot = 56*42 lbs.
„ inch = • 053 lb.
„ „ = -5268 OZ.
i 00 lbs. = 1-773 cubic foot.
lib. = -0177 „
„ = 30 • 6374 cubic inches.
lol = 1’915 »
Blasting.—Table showing amount of service powder required tc
fill borings of the undermentioned diameters ; diain. in inches,
weight in ozs. _________________
I
1'231*92
3'69:5*76
8'2
I 1 | H u If 1« It It 1 2 Diam.
3*75 4-79i 6-23 7C8 9'3b 11-07 12*9 15’06 17-sl19-6 Weight per ft.
11-25 14-37|18'69 23*01 28*05 33-21 38-7 45*18 51 • 9'58 • 88 Weight per yd.