TRACT 34?t

IN GUNNERY.

21

On account of the iron strap of 7-8 lb added at 79 inches;as above, the formula last given, for the variation in thecentre of gravity and number of oscillations, will need cor-rection, namely the formula

G = 76-54 +N = 40-27 -

670 + 6i - 86

■ 6 ,

217947

[In.

Now these formulae, by making i = 79, and b = 7-8, become

G = 76-54 + -03 =76-57,and N = 40-27 + -02 = 40'29.

And hence the corresponding radical values are nearly

p g n

678 76-57 40'29

Whichvaliies, being substituted in the two general theorems;

Viz.

G = g + -— -b, and

P + b 7

bin(inn — 140850^

N Vh —« — - N 4

581700 pg. + bi{inn + 140850 ) 9

they become

g = 16‘51 +N = 40-29 -or n = 40-29 —

■ 76-37

b, ami

678+ ft

40-29 W(i - 85-92)8920300 + bi[i + 85 939’i - 85-92,

-bi nearly,

220309

which are the new theorems hereafter to be used.

Note, the mean value of i, for the point struck the fourlast days, is 88‘82; which, used in these last formula, give;the corrected values of g and n, as inserted in their proper

columns in the table of this day’s experiments.-N° 7

is doubtful, and therefore omitted.

***

The means of. this day are as below :

Powdfer

Recoil

Veloc. of

wt

ht

guu

the ball

4

3-0 -

- 455 -

- 1124

6

4-3 -

- 615 -

- 1372

S

5-5 -

_

- 1445