296
THEORY AND PRACTICE
TRACT 37.
charges of powder, which values therefore are 19*06, and'21 - 19, and 25*47 ounces. It may be remarked also that thelengths of the gun bores, when corrected for the sphericalhollow in the bottom of the bore, is, for the four guns, 2S 53,38*43, 57*70, and 80*23. Also, that the length of the threecharges, when corrected in like manner, are 3*45, 5*99, and11*07, for the powder and bag together ; but for the powderalone only 2*54, 5*08, and 10*16. So that a general synopsispfall these dimensions and data, with the correspondent ve-locities of the ball, will be as in the following table,
The Gun.
Charge of Powder.
Wt. ofball andcharge,or valuesof p + tv.
Velocity,or the va-
Firstforce, or
1 he value
of 71.
N°
Length orvalue offt.
Wt. h.ounce:-.
Length or value
of a.
of h.
4
3*45
2*54
19*06
1100
1182
1
28*53
8
5*99
5*08
21*19
1340
1319
16
1 1*07
10*16
25*47
1430
1531
4
3 *45
2*54
19*06
1 180
1192
2
38*43
8
5*99
5*08
21*19
1480
1440
16
11*07
10*16
25*47
1660
1526
4
3*45
2*54
1906
1300
1238
3
57*70
8
5*99
5*08
21*19
1790
1622
16
11*07
10*16
25*47
2000
1670
4
3*45
2*54
19*06
1370
1231
4
80*23
8
5* 99
5*08
21*19
1940
1664
16
11*07
10*16
25*47
2200
1684
Then, by computing the values of the force n, by the pre-ceding formula, from the several data contained in the firstseven columns of this table, those values come out as theyare here arranged in the 8th or last column.
171. Here it is observable that the values of n, for thefirst force of the elastic fluid, are considerably various, bothfor all the guns and for all the charges of powder; severalof which circumstances can be easily accounted for, andsome of them appreciated. And first, it must be considered