Our lecturer was both entertaining and instructive when he dealt with old time rations; but he naturally grew weak in approaching the physiological aspect of the question.  He went through with it manfully and with a touch of humour much appreciated; whereas, for instance, he deduced facts from ’the equivalent of Mr. Joule, a gentleman whose statements he had no reason to doubt.’

Wilson was the mainstay of the subsequent discussion and put all doubtful matters in a clearer light.  ’Increase your fats (carbohydrate)’ is what science seems to say, and practice with conservativism is inclined to step cautiously in response to this urgence.  I shall, of course, go into the whole question as thoroughly as available information and experience permits.  Meanwhile it is useful to have had a discussion which aired the popular opinions.

Feeling went deepest on the subject of tea versus cocoa; admitting all that can be said concerning stimulation and reaction, I am inclined to see much in favour of tea.  Why should not one be mildly stimulated during the marching hours if one can cope with reaction by profounder rest during the hours of inaction?

Sunday, May 28.—­Quite an excitement last night.  One of the ponies (the grey which I led last year and salved from the floe) either fell or tried to lie down in his stall, his head being lashed up to the stanchions on either side.  In this condition he struggled and kicked till his body was twisted right round and his attitude extremely uncomfortable.  Very luckily his struggles were heard almost at once, and his head ropes being cut, Oates got him on his feet again.  He looked a good deal distressed at the time, but is now quite well again and has been out for his usual exercise.

Held Service as usual.

This afternoon went on ski around the bay and back across.  Little or no wind; sky clear, temperature -25 deg..  It was wonderfully mild considering the temperature—­this sounds paradoxical, but the sensation of cold does not conform to the thermometer—­it is obviously dependent on the wind and less obviously on the humidity of the air and the ice crystals floating in it.  I cannot very clearly account for this effect, but as a matter of fact I have certainly felt colder in still air at -10 deg. than I did to-day when the thermometer was down to -25 deg., other conditions apparently equal.

The amazing circumstance is that by no means can we measure the humidity, or indeed the precipitation or evaporation.  I have just been discussing with Simpson the insuperable difficulties that stand in the way of experiment in this direction, since cold air can only hold the smallest quantities of moisture, and saturation covers an extremely small range of temperature.