’ 2 $ 2 
Mr. Thompson’s Experiments 
not begin, or father that the motion of the bullet does not 
begin to be retarded, till it has pot to the diftance of two feet 
from the muzzle. The diftance, therefore, between the barrel 
and the pendulum, inftead of 12 feet, is to be eftimated at 10 
feet ; and as the bullet took up about part of a fecond in 
running over that fpace, it muft in that time have loft a velo- 
city of about 335 feet in a fecond, as will appear upon making 
the computation, and this will very exa&ly account for the 
apparent diminution of the velocity in the experiment ; for the 
difference of v the velocities, as determined by the recoil and by 
- • / . f: 
the pendulum, = 21 op - ^763 — 346 feet in a fecond, is ex- 
tremely near 33,5 feet in a fecond, the diminution of the velo- 
city, hy. the reiiftapce v as here determined. 
If the diminution qf the velocities of the bullets in the two 
i*. U • .... t *. 3 O ; t} Vtt .< - •. • ; - v ’ : / . ... , '( ■ • , 
fuhle^uent experiments be computed in like manner, it will 
turn out in the 8(kh experiment — 6< feet in a fecond. and in 
■ ■ • ; • . p , d . . y i 
the 87th .experiment = 33 feet in a .fecond ; and making thefe 
corre.£t;lopS| t h e . c o m p a r i fo n q f thp two methods of afcertaining 
the velocities^:! 
thus 
’ - c ’> •• . : ffph exp. 
Velocities fhewu by 'the pendulum, 1 7 63 
Add the diminution of the velocity'] - '• 
’ r 3 3 5 
by the refinance of the. air. 
J 
:*3 j 
Velocity by the recoil, 
The difference 
‘ul: 
2G98 
2169 
+ 11 
86th exp. 
87 th exp« 
*9'7- 
1136 
65 
33 
1382 
I 169 
143° 
1288 
+ 48 
+ 119 
> . v . ii. ’ I 
So that it appears, not withftan ding thefe corredtions, that 
the velocities in the 86th and 87th experiments, and particu- 
larly in the laft, as they were determined by the pendulum, are 
ftill 
