F 2
radiators, however, it increased again to 94% in 3 days, and remained between 90% and 97% until September 10, when the relative humidity of the outside air fell to 47%. In response the relative humidity in the basement fell to 75% on the 12th.
After fluctuating between 91% and 76% it fell to 58% on September 29 owing to another dry spell. The mean was 79% in November and 73% in December, occasionally increasing to 85% however.
The diurnal variation of temperature is negligible, as shown by the following table:-
Month Hour (H.K. Standard Time) 1923 4 8 12 16 20 November 75.28 75.23 75.24 75.25 75.27 75.23 December 72.72 72.64 72.63 72.66 72.68 72.68The annual variation is given below.
Month Mean Monthly Temperature of Basement Mean Monthly Temperature of Outside Air May 73.2 June 76.6 July 80.6 82.0 August 79.7 79.5 September 82.0 81.2 October 79.3 79.1 November 77.1 76.0 December 72.7 71.6 64.3II. METEOROLOGICAL INSTRUMENTS
Barometers.-The Marvin compensated syphon barometer has required frequent attention. In the month of June a stiff wire 6 inches long was screwed into the armature of the buzzer and adjusted so as to vibrate the vertical wire on which the pen carrier slides. This has accentuated the action of the buzzer and kept the