Upon Gun-po'wdtr, See. 271 
The fourth column (hews the difference of the computed and ; 
adual velocities, or the number of feet in a fecond by which 
the adual velocity exceeds or falls ihort of the computed : and 
in the fifth column is fet down the number of experiments 
with each charge, from the mean of which the. adual velo- 
city was determined. 
The agreement of the computed and adtual velocities wilh 
appear more ftriking, if we take the fum and differelice of thofe 
velocities with all the charges except the firft: thws, c 
Sum of the velocities, —1764. 
< — — -> 
Computed. Actual. Difference. N® of exp. 
9864 9854 ~ IO 23 
So that it appears, that the difference, or the aduai vela* 
city, was fmaller than the computed by ~ 4 t P art only at a 
mean of 23 experiments* 
But as by far the greater number of the experiments were 
made with the following charges, viz. ,290, 218, 208, 165, 
and 145 grains of powder, let us take the fum and difference 
of the computed and adfcual velocities of thofe charges : thus, 
Sum of the velocities 
A 
( > 
Computed. A&ual. Difference. N° of exp. 
5985 6044 +59 18 
Mere the agreement of the theory with the experiments is fd 
very remarkable, that we muff fuppofe it was in fome meafure 
accidental ; for the difference of the velocities in repeating the 
fame experiment is in general much greater than the difference 
of the computed and adiial velocities in this inftance ; but, I 
think, we may fairly conclude, from the refult of all thefe 
% O 2 0 trials* 
