*n] A THEORY OF BLIZZARDS 257 



warmer air from the southern limits of Lockyer's cyclones. 

 This would produce a condition of unstable equilibrium, with 

 great potentiality for movement. Since, as we have found, vol- 

 umes of cold air at different temperatures are very loath to mix, 

 the condition could not be relieved by any gradual process, but 

 continues until the stream is released by some minor cause, when, 

 the ball once started, a huge disturbance results. It seems to 

 be generally held that warm air is passing polewards from the 

 equator continuously at the high levels. It is this potentially 

 warm air which, mixed by the disturbance with the cold air 

 of the interior, gives to our winds so high a temperature. 



Such is this theory like its predecessor it is put up for 

 cockshies, and doubtless by our balloon work or by some other 

 observations it will be upset or modified. Meanwhile it is well 

 to keep one's mind alive with such problems, which mark the 

 road of advance. 



Sunday, August 6. Sunday with its usual routine. Hymn 

 singing has become a point on which we begin to take some 

 pride to ourselves. With our full attendance of singers we now 

 get a grand volume of sound. 



The day started overcast. Chalky is an excellent adjective 

 to describe the appearance of our outlook when the light is 

 much diffused and shadows poor; the scene is dull and flat. 



In the afternoon the sky cleared, the moon over Erebus gave 

 a straw colour to the dissipating clouds. This evening the air 

 is full of ice crystals and a stratus forms again. This alternation 

 of clouded and clear skies has been the routine for some time 

 now and is accompanied by the absence of wind which is de- 

 lightfully novel. 



The blood of the Crozier Party, tested by Atkinson, shows 

 a very slight increase of acidity such was to be expected, and 

 it is pleasing to note that there is no sign of scurvy. If the 

 preserved foods had tended to promote the disease, the length 

 of time and severity of conditions would certainly have brought 

 it out. I think we should be safe on the long journey. 



I have had several little chats with Wilson on the happen- 

 ings of the journey. He says there is no doubt Cherry-Garrard 

 felt the conditions most severely, though he was not only with- 

 out complaint, but continuously anxious to help others. 



Apropos, we both conclude that it is the younger people that 



VOL. I 17 



