And the conditions did not seem so bad.  “To-night it is flat calm; the sun so warm that in spite of the temperature we can stand about outside in the greatest comfort.  It is amusing to stand thus and remember the constant horrors of our situation as they were painted for us:  the sun is melting the snow on the ski, etc.  The plateau is now very flat, but we are still ascending slowly.  The sastrugi are getting more confused, predominant from the S.E.  I wonder what is in store for us.  At present everything seems to be going with extraordinary smoothness....  We feel the cold very little, the great comfort of our situation is the excellent drying effect of the sun....  Our food continues to amply satisfy.  What luck to have hit on such an excellent ration.  We really are an excellently found party ... we lie so very comfortably, warmly clothed in our comfortable bags, within our double-walled tent."[297]

Then something happened.

While Scott was 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 7151, Three Degree Depot 9392, One and a Half Degree Depot 9862, South Pole 9072 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. 11/2 deg. 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.