F 2
Mean Monthly Temperature and Relative Humidity in the Underground Chamber and in the Open Air during the year 1929.
Month 1929 In Underground Chamber In the Open Air Excess of Underground Chamber over Open Air Temperature Relative Humidity Temperature Relative Humidity Temperature Relative Humidity January, 72.4 90 62.5 79 + 9.9 + 11 February March, 70.7 89 58.9 73 +11.2 + 16 April, 72.4 79 64.9 $6 + 7.5 + 23 May, 75'0 93 71.2 75 + 3.8 + 18 June, 77'4 96 78.1 78 - 0.7 + 18 July.... 78.8 82.5 79 81.6 84 + 2.8 - 1.6 August,... 79'5 96 81.1 85 - 1.6 + 11 September 79.8 93 $1.2 79 - 1.4 +14 October, .. 78.9 86 76:5 69 + 2.4 + 17 November, 76.3 92 67'7 64 + 8.6 + 28 December, 74.4 87 64.7 78 + 9.7 + 9 Range,.... 9*7 2396II. METEOROLOGICAL INSTRUMENTS.
All the meteorological instruments were maintained in good order throughout the year.
The thermometers in use were compared with Kew Standard No. 647 in summer and winter.
The working of the electric hammer on the Nakamura Pluviograph was tested daily at 11h.
The Beckley and Dines Baxendell Anemographs were oiled and the orientation of the vanes checked once a month. The Dines Baxendell instrument continues to work satisfactorily, except at very low velocities when its action is uncertain.