THE ROYAL ARTILLERY INSTITUTION. 
79 
Table I. 
From practice at Shoehuryness , June 8-9, 1871, with the 16-pr. M.L.R. 
guns of 3'3-in. and 3'6-in. calibre respectively. 
Gun. 
Number 
of rounds 
fired. 
| Corrected 
j elevation. 
1 
j Mean time 
| of flight. 
1 
Mean 
range. 
Mean 
difference 
of range. 
Mean 
reduced 
deflection. 
* 
O / 
secs. 
yds. 
yds. 
yds. 
3'3-inch* . 
20 
2 5 
3'0 
1057 
21-9 
0-5 
3:6-inchf . 
20 
2 5 
3*3 
1187 
13'2 
0-8 
3'3-inchf . 
20 
5 3 
6*6 
2172 
20-2 
1-7 
3 6-inchf . 
20 
5 3 
6-7 
2228 
21*0 
1-2 
3'3-inchf . 
20 
10 2 
12-0 
3619 
30-3 
2-4 
3'6-inchf . 
20 
10 2 
12-1 
3596 
27'3 
3-0 
1 
The muzzle velocity of the 3'6-in. gun was found to be 1358 f.s., that 
of the 3‘3-in. gun 1307 f.s. On reference to the table, it will be seen 
that at 2° 5' the 3‘6-in. gun ranged l30 yds. farther than the 3‘3-in. 
gun, but it had T 3 oths of a second longer time to travel in. It is of 
special importance to notice the time of flight, as it has been already 
explained that the absolute height of the trajectory for any shell depends 
on its time of flight; so that if' the time of flight is shorter, the height 
of that trajectory is less. The height of the trajectory for the 3’3-in. 
gun would be 36 ft., that of the 3‘6-in. gun 43‘6ft., assuming the time 
of flight correctly taken as 3*0 and 3‘3 seconds respectively. Again, 
-j^ths of a second more time, when a shell is travelling at the rate of 
1000 ft. per second, means 300 ft., or 100 yds., in range ; thus accounting 
for the great difference in range of the two guns when fired at 2° of 
elevation. The difference in range at 5° shows a considerable falling 
off from what it was at 2°, while at 10° the 3‘3ffn. gun has the 
advantage, although still under the handicap of having less time to 
travel in. 
Another point should be considered in firing* guns with equal eleva* 
tions: the gun which has the quickest recoil in reality throws higher 
than the other, This may be explained by a well-known mechanical 
Fig. 3. 
principle. Suppose GV to represent the rate and direction of the 
Recoil not checked; 
f Recoil Checked. 
