THE SCOTTISH NATIONAL ANTARCTIC EXPEDITION. 



265 



Diurnal Range of Temioevature. 



The following tables show respectively the mean hourly values of temperature for 

 the months and the seasons. 



Hence it will be seen that the diurnal range of temperature is clearly marked in 

 Spring and Summer ; but in Autumn and Winter there is a double maximum and mini- 

 mum, which is doubtless due to the disturbing effect of cyclones, the nights in some 

 months, notably May and July, being warmer than the days, while in August the 

 nocturnal heating is observable in a less degree. (See Plate II.) 



Correcting the above values for " midnight differences," we have the following for 

 the hours of maxima and minima : — 



