Appendix F.
REPORT OF THE DIRECTOR
OF THE ROYAL OBSERVATORY, HONG KONG,
FOR THE YEAR 1981.
I. GROUNDS AND BUILDINGS.
1. The grounds were kept in order by the Forestry Department, with the assistance of the Observatory coolies. Small repairs to Buildings were carried out by the Public Works Department.
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2. Magnetic Station at Au Tau.-Apparatus for controlling the range of temperature in the magnetograph house has been received from England, and will be installed when power is available from the mains of the China Light and Power Co. It is promised in the summer of 1932.
3. Underground Chamber for Seismographs and Clocks.--- The range of temperature in the Underground Chamber was 10°.3 (F) in 1931, as against 11°.6 (F) in 1930 and 9.7 (F) in 1929. The relative humidity was usually above 95% between April 18 and September 2. The absolute range during the year was 38% in 1931, as against 46% in 1930 and 45% in 1929.
4. In the following table the mean monthly temperature and humidity in the Underground Chamber are compared with the temperature and humidity in the Open Air.