F 12
Time Signals by Wireless Telegraphy.—In addition to the time signals given by the Time Ball, and on the wireless mast, signals are sent at 10h. and 21h. by wireless telegraphy via Stonecutters. Particulars of the programme are given in the 1918 Report and in Government Notification No. 452 of 12.3.21. The service was transferred from Cape d'Aguilar to Stonecutters on May 1, 1921.
Wireless Receiving Set.—The existing set was dismounted on September 15 and re-wired, with additional apparatus, by the Superintendent of Wireless Telegraphy on December 8. With the new set the Manila time signals on a 5,000 metre wave are heard distinctly. Also the Funabashi signals. Those from Shanghai are still inaudible, though Mr. Bradshaw hopes to be able to pick them up soon.
Transit Instrument.—Observations for time were made daily with the 3-inch transit instrument and the Hipp tape chronograph by the Chinese computers, weather permitting.
The number of observations in the years 1920 and 1921 were as follows:—
1920 1921 Transits, 985 1,502 Level determination, 557 869 Azimuth, 20 50 Collimation, 20 37Transits of the Sun were utilized occasionally during 1921.
A new reticule with darker, more distinct transit lines was received from England on August 5. It was put in place the same day and the transit line intervals determined. The lines were ruled with appreciable asymmetry to prevent any possibility of bias in observing.
The azimuth and collimation determinations were made by the Chief and First Assistants from observations of the old south mark. The error so obtained was checked occasionally by observations of polar stars.
Clocks.—The Standard Sidereal clock, Dent No. 39741, was cleaned and oiled on January 13. From this date its losing rate varied from -1.12 secs. on May 31 (Barometer 29.58 Temperature 78.5) and June 18 (Barometer 29.42 Temperature 82°.5) to -0.25 sec. on December 5 (Barometer 30.15 Temperature 67°.1).
The rate during cloudy periods was usually derived from the formula:—
r = -0s.792 + 0s.575 (b - 29 ins.) + 0s.00021 (t - 50°)
where r is the computed losing rate, and b and t the mean barometric pressure and temperature, respectively, for the preceding 24 hours.
F 12
Time Signals by Wireless Telegraphy.—In addition to the time signals given by the Time Ball, and on the wireless mast. signals are sent at 10h. and 21h. by wireless telegraphy cia Stonecutters. Particulars of the programme are given in the 1918 Report and in Government Notification No. 452 of 12.3.21. The service was transferred from Cape d'Aguilar to Stonecutters on May 1, 1921.
Wireless Receiving Set.-The existing set was dismounted on September (15 and re-wired, with additional apparatus, by the Superintendent of Wireless Telegraphy on December 8. With the new set the Manila time'siguals on a 5,000 metre are are heard distinctly. Also the Funabashi signals. Those from Shanghai are still inaudible, though Mr. Bradshaw hopes to be able to pick them up soon.
Transit Instrument. --Observations for time were made daily with the 3-inch transit instrument and the Hipp tape chronograph by the Chinese computers, weather permitting.
The number of observations in the years 1920 and 1921 were as follows:--
Transits,
Level determination,
Azimuth,...
Collimation,
1920 1921
985 1,502
557
869
20
50
20
37
Transits of the Sun were utilized occasionally during 1921.
A new reticule with darker, more distinct transit lines was received from England on August 5. It was put in place the same day and the transit line intervals determined. The lines were ruled with appreciable asymmetry to prevent any possibility of bias in observing.
The azimuth and collimation determinations were made by the Chief and First Assistants from observations of the old south mark. The error so obtained was checked occasionally by observations of polar stars.
Clocks.-The Standard Sidereal clock, Dent No. 39741, was cleaned and oiled on January 13. From this date its losing rate varied from -112 secs. on May 31 (Barometer 29 58 Temper- ature 78.5) and June 18 (Barometer 29 42 Temperature 82°,5) to-0-25 sec. on December 5 (Barometer 30s ·15 Temperature
67°.1).
The rate during cloudy periods was usually derived from the formula :-
»=-0s792+0x575 (b-29 ins.) + 0x00021 (t-50°)
where r is the computed losing rate, and b and t the mean barometric pressure and temperature, respectively, for the preced. ing 24 hours.
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