THE ROYAL ARTILLERY INSTITUTION. 
345 
The gun exclusive of the cascable is 37 ,r *325 in length, inclusive, 40 ,, *435 ; 
the length of bore rifled is 32"*659; the length of the smooth-bored 
powder chamber is 3"*11. 
The 3-pr. gun weighs 191*4 lbs.; its breech preponderance is 46*9 lbs. 
The carnage, 
3. The carriage (Tig, 8, a, l, c } d, e) is of course constructed in pro¬ 
portion to the piece; it is composed of two plate-iron cheeks, a wooden 
axle,* two w r ooden wheels, and an elevating apparatus. 
The cheeks, .stiffened by riveted angle-iron, are connected together by 
a transom-bolt, elevating screw-bridge, and trail-shoe. Further, they 
are fitted with: two trunnion seats and capsquares, snugs and keys, two 
axle-bands, two recoil-rope hooks, two recoil-rope rings, two angle-iron 
keepers in rear of the elevating screw-bridge for keeping the carriage in 
its place on the saddle, and finally, a vent stopper attached by a chain to 
the right cheek of the carriage. 
The wooden axle is 39"*914 in length ; its body is plated with iron the 
whole length of its lower surface; on the body further are two linch-clouts f 
and two shoulder-clouts, and finally, on the arm two ferules and two linch¬ 
pins. 
The wheels are 37"*325 in diameter; each has five felloes, ten spokes, 
a nave with an outer and inner axle-bush, two spoke rings and two nave 
rings. 
The elevating apparatus consists of the bronze nut fastened to the 
elevating-screw bridge, and a wrought-iron elevating screw, with flanged 
head and horns. The apparatus gives an elevation of 25°, and a depression 
of 8°. 
The weight of the gun-carriage with its wheels is 206 , 18 lbs. The 
width of track is 29"*03; the height of the gun, riding on its carriage 
above the ground is 26"*697; a straight line joining the middle point 
between the trunnion seats and the point of the trail where it rests on the 
ground, forms with the horizontal line of the ground an angle of 35°; the 
total length of the carriage, measured horizontally is 61"*43. The gun and 
carriage complete weighs 398*78 lbs. The mountain gun has no limber. 
II. Ammunition, ammunition-boxes, stores, and mule equipment. 
Ammunition, 
4. The ammunition of the rifled mountain gun comprises low and high- 
angle, saluting and exercising cartridges, common and shrapnel shells, case 
shot, and the ordinary friction tubes. 
* The -weight of iron is eight times that of oak ; the strength of iron is only four times that of 
oak (for the same size): hence weight for weight and for similar sections oak is twice the strength 
of wrought-iron. Thus, an axle of iron weighing 60 lbs. might be replaced by one of oak weighing 
30 lbs., with an addition of weight for plates. The stiffness of iron and the facility which it offers 
of placing the metal where the strain is greatest, as in the girder form, are the points in its favour 
which renders it generally preferable. (Note communicated by Mr Butter, R.C.D.) 
t Clout, a patch. “ Old shoes and clouted.”—Josh. ix. 5. 
