440 
PROFESSOR F. BASHFORTH ON THE RESISTANCE OF THE 
“Resultats moyens des experiences. 
(Chaque vitesse est deduite de 30 coups.) 
Charge du 
canon. 
Premiere 
vitesse, v', a 
33 metres du 
canon. 
Derniere 
vitesse, v". 
Intervalle 
des points 
d’observation, 
X. 
Valeur de 
v'— v" 
v'v”x 
ou c. 
kilog. 
metr. 
metr. 
metr. 
1-5 
225- 1 
215-6 
464 
0-000000422 
20 
2637 
252-5 
467 
0-000000360 
2-5 
291-9 
275-9 
467 
0-000000425 
30 
309-6 
291-8 
467 
0-000000422 
35 
326-9 
306-4 
467 
0-000000438 
“ Sauf l’anomalie que presente la charge de 2 k- 0 la valeur de v , v „ x se montre sensible- 
ment constante. Laformule r=cv 3 est done suffisamment justifiee”*. The diameter of 
the shot was 0 m T623=6 ins, 39, its weight 30 k =66 lbs T4, and its form hollow ogival 
with head struck with a radius of nearly two diameters. 
In order to facilitate the comparison of this experiment with my own, I have converted 
the French into English measures. 
Charge. 
v'. 
v". 
c—2b. 
lbs. 
/•»• 
f.s. 
ft. 
3-31 
738-5 
707-4 
15224 
0-0000000391 
4-41 
865-1 
828-4 
1532-2 
0 0000000334 
5-51 
957-7 
905-2 
1532-2 
0 0000000395 
6-61 
1015-8 
957-4 
1532-2 
00000000392 
772 
1072-5 
1005-3 
1532-2 
0-0000000407 
Mean value of e or 26= 
0-0000000384 
= *0000358 if R ft. = radius of shot. 
W 
= *000000069 if d in. = diameter of shot. 
W 
The values of 25 given by my own experiments for shot of the same form were 
R 2 rV* 
•000060 ^ or -0000001042^ 
for velocities ranging from 1520 to 1270 f.s . ; so that the value of 25 deduced from my 
own experiments might be expected to be sensibly greater than its value deduced from 
M. Helie’s experiments made with lower velocities. There are three or four other 
tabular statements of less complete experiments given by M. Helie. In the present 
state of the question it is impossible to make any more exact comparison of the two 
systems of experimenting f. 
* Helie, Traite, pp. 407, 408. 
t [An extended series of experiments just completed at Shoeburyness, with 3, 5, 7, and 9-inch elongated shot, 
has shown conclusively that, although the motion of a shot may be well represented by supposing the resistance 
of the air to vary as the cube of the velocity, and to he equal to — 2bv 3 for a range of 1200 or 1300 feet, still 
