The Worst Journey in the World - Apsley Cherry-Garrard (online e reader .txt) 📗

writing the sentences you have just read, he reached the summit of the plateau and started, ever so slightly, to go downhill. The list of corrected altitudes given by Simpson in his meteorological report are of great interest: Cape Evans 0, Shambles Camp 170, Upper Glacier Depot 7,151, Three Degree Depot 9,392, One and a Half Degree Depot 9,862, South Pole 9,072 feet above sea-level.298

What happened is not quite clear, but there is no doubt that the surface became very bad, that the party began to feel the cold, and that before long Evans especially began to crock. The immediate trouble was bad surfaces. I will try and show why these surfaces should have been met in what was, you must remember, now a land which no man had travelled before.

Scott laid his One and a Half Degree Depot (i.e. 1½° or 90 miles from the Pole) on January 10. That day they started to go down, but for several days before that the plateau had been pretty flat. Time after time in the diaries you find crystals⁠—crystals⁠—crystals: crystals falling through the air, crystals bearding the sastrugi, crystals lying loose upon the snow. Sandy crystals, upon which the sun shines and which made pulling a terrible effort: when the sky clouds over they get along much better. The clouds form and disperse without visible reason. And generally the wind is in their faces.

Wright tells me that there is certain evidence in the records which may explain these crystals. Halos are caused by crystals and nearly all those logged from the bottom of the Beardmore to the Pole and back were on this stretch of country, where the land was falling. Bowers mentions that the crystals did not appear in all directions, which goes to show that the air was not always rising, but sometimes was falling and therefore not depositing its moisture. There is no doubt that the surfaces met were very variable, and it may be that the snow lay in waves. Bowers mentions big undulations for thirty miles before the Pole, and other inequalities may have been there which were not visible. There is sometimes evidence that these crystals were formed on the windward side of these waves, and carried over by a strong wind and deposited on the lee side.

It is common knowledge that as you rise in the atmosphere so the pressure decreases: in fact, it is usual to measure your height by reading the barometer. Now the air on this last stretch to the Pole was rising, for the wind was from the south, and, as we have seen, the plateau here was sloping down towards the Pole. The air, driven uphill by this southerly wind, was forced to rise. As it rose it expanded, because the pressure was less. Air which has expanded without any heat being given to it from outside, that is in a heatproof vessel, is said to expand by adiabatic expansion. Such air tends first to become saturated, and then to precipitate its moisture. These conditions were approximately fulfilled on the plateau, where the air expanded as it rose, but could get little or no heat from outside. The air therefore precipitated its moisture in the form of crystals.

Owing to the rapid changes in surfaces (on one occasion they depoted their ski because they were in a sea of sastrugi, and had to walk back for them because the snow became level and soft again) Scott guessed that the coastal mountains could not be far away, and we now know that the actual distance was only 130 miles. About the same time Scott mentions that he had been afraid that they were weakening in their pulling, but he was reassured by getting a patch of good surface and finding the sledge coming as easily as of old. On the night of January 12, eight days after leaving the Last Return Party, he writes: “At camping tonight everyone was chilled and we guessed a cold snap, but to our surprise the actual temperature was higher than last night, when we could dawdle in the sun. It is most unaccountable why we should suddenly feel the cold in this manner: partly the exhaustion of the march, but partly some damp quality in the air, I think. Little Bowers is wonderful; in spite of my protest he would take sights after we had camped tonight, after marching in the soft snow all day when we have been comparatively restful on ski.”299 On January 14, Wilson wrote: “A very cold grey thick day with a persistent breeze from the S. S. E. which we all felt considerably, but temperature was only −18° at lunch and −15° in the evening. Now just over 40 miles from the Pole.” Scott wrote the same day: “Again we noticed the cold; at lunch today all our feet were cold but this was mainly due to the bald state of our finnesko. I put some grease under the bare skin and found it make all the difference. Oates seems to be feeling the cold and fatigue more than the rest of us, but we are all very fit.” And on January 15, lunch: “We were all pretty done at camping.”300 And Wilson: “We made a depot [The Last Depot] of provisions at lunch time and went on for our last lap with nine days’ provision. We went much more easily in the afternoon, and on till 7:30 p.m. The surface was a funny mixture of smooth snow and sudden patches of sastrugi, and we occasionally appear to be on a very gradual down gradient and on a slope down from the west to east.” In the light of what happened afterwards I believe that the party was not as fit at this time as might have been expected ten days before, and that this was partly the reason why they felt the cold and found the pulling so