F 3
Dines-Baxendell Anemograph.-The bearings of the vane were oiled and its orientation checked once a month. The spindle of the float was cleaned and oiled once a week, but the instrument still works erratically at low wind velocities.
The Mean monthly results of comparisons with the records of the Beckley Anemograph from 1910-1925 are given in the following table, together with the results for 1926.
Month Mean 1910-1925 1926 January 1.94 1.97 February 1.95 2.03 March 1.89 1.89 April 2.05 1.90 May 2.17 2.03 June 2.11 1.94 July 2.24 2.12 August 2.15 2.04 September 2.20 2.21 October 2.10 2.36 November 2.01 1.96 December 1.93 1.70 Year 2.08 1.98Factor for converting the actual run of the Beckley Anemograph cups to velocities recorded by the Dines Pressure Tube Anemograph.
Thermometers.-All thermometers in use are compared with Kew Standard No. 647 in winter and summer.
III. METEOROLOGICAL OBSERVATIONS AT THE OBSERVATORY.
Automatic records of the temperature of the air and evaporation were obtained with a Richard dry and wet bulb thermograph, and of the direction and velocity of the wind with a Beckley and a Dines-Baxendell Anemograph, modified as described in the report of 1912. The amount of rain is recorded automatically by a Nakamura pluviograph and the amount of sunshine by two Campbell-Stokes universal sunshine recorders. Eye observations of barometric pressure, temperature of the air and of evaporation and the amount of cloud are made at each hour of Hong Kong Standard time. The character and direction of the motion of the clouds are observed every three hours. Daily readings are taken of self-registering maximum and minimum thermometers.