THE HONGKONG GOVERNMENT GAZETTE, 29TH JANUARY, 1887.
GOVERNMENT NOTIFICATION,-No. 38.
83
The following Report from the Director of the Observatory is published for general information.
By Command,
Colonial Secretary's Office, Hongkong, 29th January, 1887.
FREDERICK Stewart,
Acting Colonial Secretary.
REPORT ON THE TIME-SERVICE IN 1886, AND MICROMETRIC
MEASURES OF PLANETS.
The transit-instrument was throughout the past year used exclusively for ascertaining the error of the sidereal standard clock. The number of transits observed was 193, and the inclination of the axis was determined 65 times. The azimuthal deviation was whenever necessary corrected by aid of the distant meridian-mark, but this as well as any outstanding error of collimation was eliminated by observing objects very near the zenith,-one passing the meridian south and the other north of the zenith, and reversing the instrument before the transit of the second star. The inclination cannot be similarly eliminated without using an artificial horizon, but this is not practicable as zenith-stars could not be observed reflected from the mercury, whence the necessity for levelling every night when transits are secured except occasionally for a few nights, if the temperature is quite constant. The inclination affects the observed clock-error with fully its whole amount, but of course the factor is smaller within the tropics than in a higher latitude.
The sidereal standard clock has been going without interruption since the beginning of September, 1885, since which epoch the case has not been opened nor the hands touched. It is intended that the rate should be altered in another year. The mean daily rates during ten-day periods are exhibited in the following table, where means gaining rate.
RATE OF SIDEREAL STANDARD CLOCK IN 1886.
Period.
Rate.
Temp. Bar.
Period.
Rate.
Temp. Bar.
1886.
1886.
January
26- 5,.......
-0°.86
62°.9
30.18
July
4-14,.
- 2o.78
81°.3
29.72
5-15,..
0.78
63 .1
.12
14-24,.
2.92
80.2
.63
""
15-25,
0.86
62 .9
29.92
"
24- 3,.
3.09
82 .6
.62
05
25- 4,....
0.78
56 .2
30.01
August
3-13,
3.24
83 .3
66
February 4-14,..
0.55
55.7
.03
13-23,
3.28
83..0
56
39
14-24,
0.58
55 .8
.12
23- 2,.
3..27
80.5
.71
>>
March
24- 6,... 6-16,.
0.81 60 .1
.01
September 2-12,.
3.26
80.3
.71
16-26;.........
1.04 1.28 66.5
62 .4
29.97
12-22,..
3.23
81.6
.69
""
.91
22- 2,..
3.25
79 .3
.83
39
26- 5,.........
1.42 64.8
.92
October
2-12,.
3.14
79..2
.80
April
5-15,
1.73
71.5
.82
12-22,.
3.09
77.2
.88
"
15-25,
1.78
68 .9
.83
22- 1,.
3.11
77 .5
.95
25- 5,.
1.79
70.1
.89
November
1-11,.
2.80
72..3
30.03
May
5-15,......
1.95
72..9
.79
11-21,.
2.77
70.5
.00
""
15-25,.
2.26
79..2
.79
21- 1,..
2.55
69 .1
.05.
"
25 4,..
2.38 78.9
.74
December
1-11,..
2.41
64 .7
.12
39
June
4-14,.
2.52
80.0
.64
11-21,.
2.17
62.0
.06
19
14-24,.
2.57 79.7
.70
21-31,.
2.15
60..4
.07
""
24- 4,
2.70 82.9
.70
"
The chronometers are compared on Mondays and Saturdays shortly before 1 p. The first named chronometer was used only as a hackwatch. Their daily rates ( + means losing, - gaining rate) were as follows:-
No comments yet.
Private notes are available after approval.