Month and
F 2
Relative Humidity in Underground Chamber.
Year Oh. 4. Sh. Noon. 161. 20h. Range.
1923 % % % 80.6 80'z 80'0 % %% % 78.1 78°c % 78.8 2:6
Nov. 1924 66.8 66.3 64.7 63-8 64.7 66.3 3.0
1923 73'5 7375 73'0 72'9 77 72'2 18
Dee. 1924 609 60*8 60°3 58-7 59'5 60.4 2.2
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. As the air in the Underground Chamber is always still, humidity tables for calm air have been computed and used for obtaining the relative humidity from the readings of these dry and wet bulb thermometers.
Mean Monthly Temperature and Relative Humidity in the Underground Chamber and in the Open Air, during the year 1924.
In Underground Chamber. In Open Air. Excess of Under-ground Chamber over Open Air. Month 1924. Temper-ature Relative Humidity Temper-ature Relative Humidity Temper-ature Relative Humidity January, 70.6 76 52.7 81 + 8.2 - 5 February,... 69.1 79 60.3 86 + 8.8 - 7 March, 687 79 62-5 79 + 6.2 0 April, 704 88 69.3 85 + 11 +3 May, 74.5 95 79.6 82 - 5'1 +13 June, 770 80*5 83 in in 3'5 July, 79'7 94 817 83 - 2.0 +11 August. 80'5 92 819 82 - 1.4 +10 September,. 80.6 89 82-2 -8 - 1.6 October, 79°1 81 76'5 7 + 2.6 +10 November,.. 76-3 65 68.2 57 + 8.1 + 8 December,.. 72.9 60 619 61 +11.0 - 1 Range... 119 35 21.9 29It will be seen that while the range of temperature in the Underground Chamber is only a little more than half the range in