F 11
Comparison of Barometers.-The corrections to ships' barometers are usually obtained by comparing their readings while at Hongkong with those of the Observatory Standard. Occasionally ship captains bring their barometers to the Observatory to be compared with the Observatory Standard.
VII. MAGNETIC OBSERVATIONS.
Magnetic horizontal force, declination, and dip are observed once a month. In the dip observations 4 needles are used in rotation, the result for each month being the mean of determinations with two needles.
In the following table are given the annual values of the magnetic elements in 1925 as derived from observations made in the new magnetic hut with magnetometer Elliott 83 and dip circle Dover 71:-
Declination (West)... Dip (North).... Horizontal Force (C. G. S. unit) Vertical Force (C. G. S. unit) Total Force (C. G. S. unit) / 0.27.2 30.41.8 0.37325 0.22159 0.43408A site for a new magnetic observatory was selected in the vicinity of the Au Tan Police Station, approximately 14 miles north-west from the Royal Observatory (30 miles by road). It is situated in the midst of extensive rice cultivation, and would appear to be reasonably safeguarded from future building encroachments. The erection of the necessary buildings has been postponed on account of the existing financial depression.
VIII.-TIME SERVICE.
Time Ball.-The Time Ball on Kowloon Signal Hill is dropped at 10 a.m. and 4 p.m., daily, except on Saturdays when it is dropped at 10 a.m. and 1 p.m., and on Sundays and Holidays when it is dropped at 10 a.m. only (120th Meridian Time).
The Ball is hoisted half mast at the 55th minute and full mast at the 57th minute. If the ball fails to drop at the correct time it is lowered at 5 minutes past the hour and the ordinary routine repeated at the following hour, if possible.
Time Signals are also given at night by means of three white lamps mounted vertically on the Observatory radio mast. The lights are extinguished momentarily every second from 8h. 55m. to 9h. 0m. p.m., except at the 28th, 29th, 54th, 55th, 56th, 57th, 58th and 59th seconds, of each minute. The 9 p.m. signals were repeated at midnight on December 31st, the last signal indicating the close of the year 1925. The hours refer to Hongkong Standard Time (8 hours East of Greenwich).
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F 11
Comparison of Barometers.-The corrections to ships' baro- meters are usually obtained by comparing their readings while at Hongkong with those of the Observatory Standard. Occasionally ship captains bring their barometers to the Observatory to be compared with the Observatory Standard.
VII. MAGNETIC OBSERVATIONS.
Magnetic horizontal force, declination, and dip are observed once a month. In the dip observations 4 needles are used in rotation, the result for each month being the mean of determina- tions with two needles.
In the following table are given the annual values of the magnetic elements in 1925 as derived from observations made in the new magnetic hut with magnetometer Elliott 83 and dip circle Dover 71:-
Declination (West)...
Dip (North)....
Horizontal Force (C. G. S. unit) Vertical Force (C. G. S. unit) Total Force (C, G. S. unit)
/
0.27.2
30.41.8
0-37325
0.22159
0-43408
A site for a new magnetic observatory was selected in the vicinity of the Au Tan Police Station, approximately 14 miles north-west from the Royal Observatory (30 miles by road). It is situated in the midst of extensive rice cultivation, and would appear to be reasonably safe-guarded from future building encroachments. The erection of the necessary buildings has been postponed on account of the existing financial depression.
VIII.-TIME SERVICE.
Time Ball.-The Time Ball on Kowloon Signal Hill is dropped at 10 a.m, and 4 p.m., daily, except on Saturdays when it is dropped at 10 a.m. and 1 p.m., and on Sundays and Holidays when it is dropped at 10 a.m. only (120th Meridian Time).
The Ball is hoisted half mast at the 55th minute and full mast at the 57th minute. If the ball fails to drop at the correct time it is lowered at 5 minutes past the hour and the ordinary routine repeated at the following hour, if possible.
Time Signals are also given at night by means of three white lamps mounted vertically on the Observatory radio mast. The lights are extinguished momentarily every second from 8h. 55m. to 9h. Om. p.m., except at the 28th, 29th, 54th, 55th, 56th, 57th, 58th and 59th seconds, of each minute. The 9 p.m. signals were repeated at midnight on December 31st, the last signal indicating the close of the year 1925. The hours refer to Hongkong Standard Time (8 hours East of Greenwich).
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