FA, P. Barnard on the Explosive Force of Gunpowder. 255 
Kind rvais |Velocity | Velocit sty | Diff. obs. | Diff. cor. | Pres. in atm. 
Approx. |No Y | Velocit hich Id 
f iNo,| “PF ¢ nF which wou 
ns °-\val. of 2.| Expansion. lobserved.| yy orange. omp' ted. oloc le | pater — cor. 
wes] 1) 34 1439 | 1596 | 1687 | 248 9 4483 
ie ae 28+ | 1563 | 1720 | 1790 | 2927 40 4621 
of t 21- 1741 | 1898 | 1954 | 213 56 4722 
ae 43+ | 1370 | 1508 | 1563 | 193 55 4659 
33 4 84+ | 1486 | 1624 | 1689 | 203 65 4629 
ohn 4 29- 1635 | 1773 | 1793 | 158 20 4896 
“1 i ee | 21+ | 1884] 1972 | 1958 | 194 | -14 5081 
Bs! f L 61 1878 | 1516 | 1618 | 240 102 4396 
a) 9 6t 40+ | 1674 | 1812 | 1865 | 191 4724 
S 2/10) 4+ 80 1906 46 | 140 ‘ 4999 
. {il 4 68 1444 | 1582 | 1635 | 191 53 4688 
3 [1 4 45 1742 | 1880 | 1888 | 146 8 4965 
kanal TT" ee 34- 1951 | 2089 | 2073 | 122 | -1E¢ 5081 
= |14) 3 27- 2098 | 2286 | 2217 | 119 | -19 5092 
w 115, 2239 | 2377 | 2831 92 | -46 5206 
§ | 16 +5 19- 2300 | 2428 | 2422 | 122 | -1¢ 5074 
i ¢% 16+ | 2824 | 2462 | 2498 174 | +86 4863 
ES Bp 3 68- 1240 | 1394 | 1481 91 37 4754 
6 aR eae | 5« 1440 | 1594 | 1591 | 1651 me 5027 
te | 2C 3 83+ | 1723 | 1877 | 1829 06 -48 5274 
USE. A 25 1870 | 2024 | 2000 30 | -24 5127 
By rv oe 60+ | 1271 | 1421 | 1421 50 0 5007 
SSiosi 3 45 1430 | 1580 | 1577 47. | =38 5023 
ae} 24} ¢ 30- 1640 | 1790 | 1811 71 21 4891 
ae dd a 22 1780 | 1930 | 1976 96 46 47174 
By Mean of pressures, 4882 
would produce a mean effect upon velocity equal to aim 
about one-eightieth of the whole. But, if we take the time in 
the gun at 0*-006, and admit that the conclusions of Piobert pe 
regard to the rapidity of combustion are yin 
we shall be forced to allow that only a fasion of the meet 
elastic energy of the generated gases comes into play; and that 
therefore, nid computed velocities ney (of we have correctly de- 
termin € maximum pressure) are greatly in excess 0: 
‘th 
the velocities Agee observed; and 1 should probably exceed 
em a number o 
It is probable rie Sethiag experiment would prove, that, con- 
trary to Piobert’s opinion, the combustion of gunpowder must 
cumstances in which it is most easy directly to observe it. But 
it is not by any means pee ta that the a of rie Be = 
ever great enough to permit us to discard t consideratio 
time from among the dratsians which must oo into this probe 
lem. On the contrary, the pressures registered by man’s 
pesemee when rifle powder and large grained cannon powder 
successively fired in the same gun and with the same ber 
of projectile, show that the evolution of gas in the second case i 
