THE ROYAL ARTILLERY INSTITUTION. 
347 
Opposite 1263*79, in Table IX., we have 
1*419, 
,n 
but t - = 7*137, 
w 
giving 8*556, 
opposite which we find 769*75 as remaining velocity. 
Turning to Table VIII., we have 
opposite 1263*79 the value 2069, 
„ 769*75 „ 8719, 
and JS = the difference = 6650 ft. 
.\ S cos Ej 2 = 11561, 
Wt- 130*7, 
11691*7 ft. 
Therefore the true range will be 3897*2 yds. It is, in fact, as observed, 
3890 yds. 
For the third series, comprising six rounds, we have 
f.s. 
WcosDcosJE— 15*32, 
.*. V + W cos D cos E — 1289*32; 
because the direction of the wind is opposed to that of the projectile. 
Proceeding as before, we arrive at 776*6 as the final velocity, which 
will give 
ft. 
S cos E Z = 11510 
d 2 
less W cos Dt = 193 
11317 ft. 
Therefore the true range will be 3772 yds., and it is observed aS 
3769 yds. 
If there were no wind, a reference to the tables will show us that the 
range of the 40-pr., under the above conditions (except as to wind)> 
would be 3842 yds .; so that the correction applied for the wind will in 
the second series be 55 yds., and in the third 73 yds. 
In the fourth series, comprising ten rounds, fired at an elevation of 
2° 6', the wind, as estimated, gives a range of 1211 yds., the observed 
range being 1200. 
These results are very close, when it is considered how rough a 
method is employed for the registration of the wind. In the fourth 
series the wind was probably less than 4, and in the third it appears 
likely (from the large deviation) that the wind was more than 3. 
