94 Mr. Herschel/s account of a series of observations 
July 12. All the signals, the blue light excepted, were this 
evening visible to the naked eye ; the blue light could not 
be seen at all :* the times of the explosions were this even- 
ing all observed with telescopes. 
Rockets. 
App 1 Time. I. 
II. 
Mean. 
: 1 
9 h 3 1 5 ° s 
9 h 3 i m 49 . 8 s 
u 
49.90 s 
2 
41 50,75 
41 50.6 
<L) 
> 
Ut 
<D 
50.67 
3 
51 50.0 
51 50.0 
CO 
jo 
0 
50.00 
4 
10 1 51.5 
10 1 51.5 
u 
51.50 
5 
11 51.8 
11 52.2 
IS 
4-* 
52.00 
: 6 
21 53.0 
cn 
N 
00 
c 
a 
52.90 
7 
3 1 5 l -° 
31 51.0 
bJO 
.S 
51.00 
8 
41 51.2 
4 i 5»-3 
a 
<L> 
51.25 
9 
51 48.0 
51 48.0 
<u 
CO 
48.00 
10 
1 1 1 49.8 
11 1 49.7 
rC 
H 
49-75 
Comparison before 
After 
Chronometer. 
9 h 
ii 
1 1 m 
12 
Clock. 
i6 h 32 m 19.94 s 
18 33 39.80 
Mean Error and Rate of Transit Clock. 
Mean of 5 * 8 I Corresponding error. I Rate. 
i6 h 24“ J 48.27 s I — 0.08 
From mean comparison on nth, to ditto on 12th, chronometer gained 1.02*. 
Chronometer fast i m 18.99 s . 
Rockets 1 and 6 exploded twice, at an interval of about three seconds. The 
first explosion, in each case, was the one observed ; the second, not being expected, 
was lost. 
None was fired. (H.) 
