\)2 ; 'transactions of the South African Philosophical Society. 



TABLE VIII. 



Some Comparative Statistics of Solar Radiation. 





Altitude 

 in Feet. 



Cloud 



at 

 Noon. 



Relative 

 Humidity 

 at Noon. 



Dew- 

 point 



at 

 Noon. 



Difference of Maxima. 



Station. 



Ob- 

 served. 



Cor- 

 rected 

 to Cloud 

 — 30 °L 



Cor- 

 rected to 

 Humid- 

 ity 



Cor- 

 rected to 

 Dew- 

 point 















OV /Q. 



= 36 %. 



= 44o. 







% 



% 



o 



o 



o 











Kimberley 



3,950 



30 



36 



44-3 



58-6 



58-6 



58-6 



58-6 



Leh 



11,540 



54 



51 



31-6 



63-4 



61-4 



57-6 



55-8 



Chakrata.. 



7,050 



48 



52 



45-6 



67-9 



65-9 



63-2 



63-6 



Kanikhet.. 



6,070 



44 



47 



48-6 



57-5 



56-0 



54-2 



55-3 



Dehra .... 



2,230 



38 



55 



60-8 



54-9 



53-9 



50-7 



54-9 



Koorkee . . 



890 



29 



47 



59-7 ' 



53-3 



53-3 



51-5 



55-4 



Bareilly . . 



570 



31 



50 



62-4 



52-0 



52-0 



41-7 



54-4 



Adelaide. . 



140 



51 



46 



50-2 



57-7 



55-7 



54-0 



55-6 



Cordoba . . 



1,440 



47 



51 



51-3 



55-3 



53-6 



51-1 



52-9 



The Indian values in the first six columns of Table VIII. are 

 extracted chiefly from a discussion of the meteorology of the North- 

 West Himalaya, by the late S. A. Hill.* Values for Kenilworth 

 (Kimberley), Adelaide, and Cordoba are inserted for comparison. 

 The quantities for the different places are not strictly comparable. 

 At Cordoba the mean difference of maxima only applies to clear 

 days, since readings of the black bulb are not taken on cloudy days. 

 The amount of cloud at the Indian stations is the mean of all the 

 observations at whatever time of the day they are made, and this 

 may differ somewhat from the true noon values. At Kenilworth the 

 amount of cloud is the mean of observations at XI. and XIV. The 

 humidity percentages for the Indian stations are also the means of 

 all the observations. I have deducted 15 per cent, from each to get 

 the approximate noon percentages. The humidity percentages and 

 dew-points for Adelaide are derived from the maximum values of 

 dry and wet bulbs, which are not usually attained at noon, nor 

 do they necessarily occur simultaneously. I have left the Indian 

 dew-points untouched, not having materials wherewith to correct 

 them for daily range. 



Indian meteorologists were never very friendly to the black bulb 

 thermometer. (Why do they use it at all?) Hill commented as 

 follows : "If the air were absolutely diathermanous the altitude 

 of the sun above the horizon and the vertical thickness of the 

 atmosphere above the [place of observation should have no effect 



* S. A. Hill, Indian Met. Memoirs, vol. i., p. 377. 



