Mean Monthly Temperature and Relative Humidity in the Underground Chamber and in the Open Air during the year 1931.
Month In Underground Chamber In the Open Air Excess of Underground Chamber over Open Air Temperature Relative Humidity Temperature Relative Humidity Temperature Relative Humidity January 73.2 83 61.4 +11.8 February 71.7 77 61.3 85 +10.4 -8 March 70.1 80 63.6 80 +6.5 April 71.7 May 74.2 70.9 +3.3 June 91 95 -4 July 78.7 87 77.0 96 +1.7 -9 August 79.5 81 81.4 96 -1.9 -15 82.7 95 82.7 83 September 80.4 93 81.2 -0.8 October 79.2 81 74.4 67 +4.8 +14 November 77.2 79 70.4 66 +6.8 +13 December 74.5 78 63.3 72 +11.2 +6 Range 10.3 14II.-METEOROLOGICAL INSTRUMENTS.
5. All the meteorological instruments were maintained in good order throughout the year.
6. The thermometers in use were compared with Kew Standard No. 647 in summer and winter.
7. The working of the electric hammer on the Nakamura Pluviograph was tested daily at 11h.
8. The Beckley and Dines Baxendell Anemographs were oiled and the orientation of the vanes was checked once a month. The Dines Baxendell instrument continues to work satisfactorily, except at very low velocities when its action is uncertain. The mounting of the Dines instrument, which had become badly corroded, was replaced by the P.W.D. in August. The scale value was tested on October 30 and November 3. In the following table the results are compared with those obtained in 1927.