218 
MINUTES OF PROCEEDINGS OF 
Mean 
Tn English 
In metric 
weight. 
measure. 
measure. 
C. 
C. 
lbs. 
ft. 
metres. 
Five heavv shells . 
. 2949 
12,883 
3926-0 
Five medium shells . 
11,420 
3480-3 
Nine light shells. 
10,419 
3175-3 
Mean of all. 
. 2594 
11,332 
3453*1 
These weights include in each case a charge of sand and sawdust of about 
equal weight with the proper bursting charge of the shell, viz. 405 lbs. to 
487 lbs. (p. 212). If the resistance of the air to masses of such weight, 
projected with low velocities, were negligible, we should expect to find the 
ranges of shells of dissimilar weight projected at the same angle and by 
equal charges, as exactly proportionable inversely to their weights. Jfor in 
vacuo, if X and X x represent the ranges of two shells, whose weights are 
P, P 2 and V, Vi their respective initial velocities, then 
V s , ' 
rp 
A 
p ' 
We have the data for four comparisons of this nature ; but as the angles of 
elevation were not identical, a correction must first be applied to reduce 
them all to 45°. If the resistance is nil, or very small, 
X _sin 2 (J> 
X t ~ sin 2 0,' 
Table III. 
Comparison of Ranges of Shells of different Weights fired with the same 
Charge . 
Charge. 
Shell. 
Angle 
Observed 
range. 
Range 
reduced to 
45°. 
V 
p 
X 
■Zi 
lbs. 
lbs. 
degs. 
ft. 
ft. 
40 
2352 
48| 
5133 
6153 
— 
— 
40 
2416 
45 
5100 
6100 
— 
— 
Mean. 
2384 
— 
5116 
5126 
1-233 
1-146 
40 
2660 
4869 
_ 
_ 
_ 
40 
2660 
42-i- 
5043 
— 
— 
— 
Mean. 
2660 
— 
4956 
4993 
1-105 
1-116 
40 
■ 2940 
42£ 
4575 
_ 
__ 
_ 
40 
2940 
42i 
4473 
— 
— 
— 
40 
2940 
42i 
4404 
— 
— 
— 
40 
2940 
42i 
4317 
— 
— 
— 
Mean. 
2940 
— 
4440 
4473 
1-000 
— 
* 50 
2403 
45 
6360 
__ 
— 
50 
2373 
45 
6300 
6330 
1-250 
1-214 
50 
2986 
48i 
5196 
5213 
1-000 
— 
60 
2385 
45 
6969 
6969 
1-092 
1-019 
60 
2600 
48i 
6813 
6839 
1-000 
— 
70 
2400 
45 
8274 
8274 
1-061 
1-039 
70 
2548 
48i 
7932 
7962 
1-000 
— 
Means ... 
— 
— 
— 
1-150 
1-107 
