It is calculated that the body requires certain proportions of fat, carbohydrates and proteins to do certain work under certain conditions:  but just what the absolute quantities are is not ascertained.  The work of the Polar Party was laborious:  the temperatures (the most important of the conditions) varied from comparative warmth up and down the glacier to an average of about -20 deg. in the rarefied air of the plateau.  The temperatures met by them on their return over the Barrier were not really low for more than a week, and then there came quite commonly minus thirties during the day with a further drop to minus forties at night, when for a time the sun was below the horizon.  These temperatures, which are not very terrible to men who are fresh and whose clothing is new, were ghastly to these men who had striven night and day almost ceaselessly for four months on, as I maintain, insufficient food.  Did these temperatures kill them?

Undoubtedly the low temperatures caused their death, inasmuch as they would have lived had the temperatures remained high.  But Evans would not have lived:  he died before the low temperatures occurred.  What killed Evans?  And why did the other men weaken as they did, though they were eating full rations and more?  Weaken so much that in the end they starved to death?

I have always had a doubt whether the weather conditions were sufficient to cause the tragedy.  These men on full rations were supposed to be eating food of sufficient value to enable them to do the work they were doing, under the conditions which they actually met until the end of February, without loss of strength.  They had more than their full rations, but the conditions in March were much worse than they imagined to be possible:  when three survivors out of the five pitched their Last Camp they were in a terrible state.  After the war I found that Atkinson had come to wonder much as I, but he had gone farther, for he had the values of our rations worked out by a chemical expert according to the latest knowledge and standards.  I may add that, being in command after Scott’s death, he increased the ration for the next year’s sledging, so I suppose he had already come to the conclusion that the previous ration was not sufficient.  The following are some of the data for which I am indebted to him:  the whole subject will be investigated by him and the results published in a more detailed form.

According to the most modern standards the food requirements for laborious work at a temperature of zero Fahr. (which is a fair Barrier average temperature to take) are 7714 calories to produce 10,069 foot-tons of work.  The actual Barrier ration which we used would generate 4003 calories, equivalent to 5331 foot-tons of work.  Similar requirements for laborious work at -10 deg.  Fahr. (which is a high average plateau temperature) are 8500 calories to produce 11,094 foot-tons of work.  The actual Summit ration would generate 4889 calories, equivalent to 6608 foot-tons of work.  These requirements are calculated for total absorption of all food-stuffs:  but in practice, by visual proof, this does not take place:  this is especially noticeable in the case of fats, a quantity of which were digested neither by men, ponies, nor dogs.