446 ON THE LAW OP THE RESISTANCE OE THE AIR TO RIFLED PROJECTILES. 
“ Details of bullet, &c. 
“Metford’s match-rifle: calibre 0-4605 inch. 
“ Charge : 90 grains, Curtis and Harvey’s No. 5 powder. 
“ length of bullet . . . 1*45 inch. 
“Diameter at base . . . 0-451 „ 
^ inch from base 0*45 „ 
f inch from base 0-447 ,, 
“ Weight : 530 grains. 
“ Material : lead hardened with alloy. 
“ Shape : cup-shaped in rear, nearly cylindrical for the first inch, and gradually rounding 
off from there to a spherical or paraboloidal head, not pointed.” 
These notes were not given to me until after my calculations had been made. It will 
be observed that the data originally supplied, and from which I worked, are those of 
Table 2. This appears to be the most reliable, being very near the mean of the other 
two. 
On the whole, I consider myself singularly fortunate in having had such a very good 
series of experiments from which to calculate. 
It will not fail to be noticed that the velocity of sound is intermediate between the 
initial and final velocities of the bullets at the longer ranges. 
Note added 3rd August 1868. — For the sake of comparison with other results, I give 
the reduction of this coefficient of resistance to the standard of one pound weight avoir* 
dupois, and one inch transverse section, on the (doubtful) assumption that the coefficient 
varies inversely as the weight, and directly as the transverse section. 
Coefficient reduced to 1 lb. weight and to one square inch section 0-00000 01267, 
Ditto, and to one circular inch section . 0-00000 00995. 
