F 13
Time Signals by Radio Telegraphy.-In addition to the time signals given by the time ball, and on the radio mast, signals are broadcast at 10h. and 21h. by radio-telegraphy, via Cape D'Aguilar. Particulars of the programme are given in Government Notification No. 322 of the 1st June, 1928.
Observations of the rhythmic radio time signals emitted by Nauen at 8h. a.m., Hong Kong Standard Time, have been made daily, whenever possible, during the year. The observations have been utilized for clock regulation during cloudy weather.
Longitude Determination.-During the period Jan. 1st, 1927-December 31st, 1929, 285 observations of the Bordeaux time signal were observed, giving a longitude of Hong Kong of 7h. 36m. 41.28s. East of Greenwich. During the same period, 916 observations of the Nauen time signal were made, giving a longitude of 7h. 36m. 41.21s. east of Greenwich. The mean result from observations of both stations is therefore 7h. 36m. 41.25s. This result is identical with that obtained by means of 13 simultaneous observations of the Bordeaux time signal observed by Hong Kong and Greenwich in September-November, 1925. Both results need a correction of 0.03s for time of transit of the signal, and as a result of all observations made at the Royal Observatory, Hong Kong, the longitude may be taken as 7h. 36m. 41.22s. east of Greenwich. The 35 observations of the Bordeaux time signal made during October and November 1926 were sent to the "Commission Internationale des Longitudes par T.S.F." and in "La Revision des Longitudes Mondiales" the resulting longitude of Hong Kong is given as 7h. 36m. 41.19s. east of Greenwich. It is not proposed at present to alter the adopted longitude of the observatory, namely, 7h. 36m. 41.25s. east of Greenwich.
Transit Instrument.-Routine transit and level observations were made by the Chinese computers throughout the year. The Collimation and Azimuth determinations and occasional transit observations were made by the Chief and First Assistants.
The number of observations in the years 1928 and 1929 was as follows:-
1928 1929 Transits 1200 1111 Level determinations 620 562 Azimuth determinations (mark) 31 32 Azimuth determinations (transit of circumpolar stars) 276 271 Collimation determinations (mark) 41 35Clocks. Sidereal Clock Cottingham and Mercer, No. 507, has been in use as the Observatory Standard throughout the year. Its performance was again marked by a steady increase of...
F 13
Time Signals by Radio Telegraphy.-In addition to the time signals given by the time ball, and on the radio mast, signals are broadcast at 10h. and 21h. by radio-telegraphy, via Cape D'aguilar. Particulars of the programme are given in Govern- ment Notification No. 322 of the 1st June, 1928.
Observations of the rhythmic radio time signals emitted by Nauen at 8h. a.m., Hong Kong Standard Time, have been made daily, whenever possible, during the year. The observations have been utilized for clock regulation during cloudy weather.
Longitude Determination.-During the period Jan. 1st, 1927-December 31st, 1929, 285 observations of the Bordeaux time signal were observed, giving a longitude of Hong Kong of 7h. 36m. 41.28s. East of Greenwich. During the same period, 916 observations of the Nauen time signal were made, giving a longitude of 7h. 36m. 41.21s. east of Greenwich. The mean result from observations of both stations is therefore 7h. 36m. 41.25s. This result is identical with that obtained by means of 13 simultaneous observations of the Bordeaux time signal observed by Hong Kong and Greenwich in September- November, 1925. Both results need a correction of 0.03s for time of transit of the signal, and as a result of all observations made at the Roval Observatory, Hong Kong, the longitude may be taken as 7h. 36m. 41.22s. east of Greenwich. The 35 observa- tions of the Bordeaux time signal made during October and November 1926 were sent to the "Commission Internationale des Longitudes par T.S.F." and in "La Revision des Longitudes Mondiales" the resulting longitude of Hong Kong is given as 7h. 36m. 41.19s. east of Greenwich. It is not
It is not proposed at present to alter the adopted longitude of the observatory, name. ly, 7h. 36m. 41.25s. enst of Greenwich.
Transit Instrument.-Routine transit and level observations were made by the Chinese computers throughout the year. The Collimation and Azimuth determinations and occasional transit observations were made by the Chief and First Assistants.
The number of observations in the vears 1928 and 1929 was as follows:-
Transits
Level determinations
Azimuth determinations (mark)
Azimuth determinations (transit of
circumpolar stars)
1928 1929
1200 1111
620 562
31 32
276 271
Collimation determinations (mark) 41
35
Clocks. Sidereal Clock Cottingham and Mercer, No. 507, has been in use as the Observatory Standard throughout the Its performance was again marked by a steady increase of
year.
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