XC111 
OBSERVATIONS to ascertain the Error of No. 259 on Mean Time at the 
Observatory, previous to the Sailing of the Expedition from Winter Harbour 
in 1820. 
1S20 
Time by 259 
Obser- 
ver 
Observed Altitude 
Baro- 
meter 
Ther- 
mome- 
ter 
Mean Time 
259 Fast of Mean Time 
Remarks 
H M S 
O / // 
INCHES 
O 
H M S 
H M S 
July 24 
12 OS 16.3 
s 
43 05 OS 0 
29.78 
50 
5 32 29.22 
6 35 47. 08^ 
i 99 
12 16 55 
s 
41 56 48 O 
5 41 07.9 
6 35 47.1 
The Altitudes 
H M S 
were ob- 
12 23 59.83 
s 
41 01 01 0 
, , 
5 48 13.2 
6 35 46.63 
6 35 47.14 
served with a 
\ 
Sextant and 
/ At midnight of 
mercurial 
99 
26 OS 52 
s 
4S 39 45 Q 
29.58 
48 
19 33 04.27 
6 35 47.73 
the 24th of July 
horizon 
99 
26 16 40.3 
s 
49 38 29 O 
. . . 
19 40 53.3 
! 6 35 47 
99 
26 24 36.3 
s 
50 37 IS 0 
• • 
19 48 49.2 
6 35 47.28^ 
H M S 
The Sun’s Transit at noon of the 24th, was at 6 35 44.3 by No. 259 
And at noon of the 25th, at 6 35 45.64 
July 24th, midnight,. . . 6 35 44.97 
At which time No. 259 was actually fast of Mean") 
, J l 6 35 47.14 
Time, as shewn by the preceeding Observations J 
Difference . . . . 2.17 
Consequently this difference, or 2 seconds, omitting the decimal parts, being 
added to the time shewn by No. 259 at the Sun’s Transit, gave the error of 
the Chronometer on Mean Time. 
On the 31st of July, being the day preceding the sailing of the Expedition, 
No. 259 shewed 6 35 54.32 at the Sun’s noon Transit, and was therefore 
H M S H M S 
6 35 56.3 fast of mean Observatory Time at Winter Harbour, and 0 45 13 
slow of Greenwich Time. 
m 2 
