214 



PRESSURE, WINDS AND WEATHER. 



a descent to the Pole at the rate of 83 feet per geograjihical mile (see page 

 292). The barometer readings have been corrected for this change of height and 

 plotted as the lower curve on plate V at the end of this volume, the two 

 upper curves being those for Cape Evans and Framheim respectively. 

 (6) The observations taken by Captain Scott when he made his journey to the Western 

 Plateau by way of the Ferrar Glacier in November 1903. The part of the 

 plateau visited on this occasion lay due west of McMurdo Sound and a 

 point nearly 200 miles to the west of the edge of the plateau was reached. 

 Owing to the want of sufficient details as to the position of the party when 

 each set of observations was taken, it has not been possible to correct 

 the observations for change of height, but it is obvious from the curves 

 shown on plate V that the change of height does not affect our present 

 discussion. 



We will now examine plate V showing the changes of the barometer on the Polar 

 Plateau between December 31st and January 30th, 1910-11. Unforturately during this period 

 the pressure waves were not very pronounced even at sea-level, but fairly well marked 

 positions of maximum and minimum pressure can be detected on the Framheim curve. These 

 are marked on the curve by the numbers I to IV. There is no doubt that each one of 

 these points of inflexion can be detected on the ciu've for the plateau. The rise of pressure 

 on the 14th January with the following maximum on the 15th is particularly well marked. 

 The respective changes of pressure and the times of occurrence are tabulated for each station 

 in the following table. Owing to the observations being made at Framheim and on the 

 plateau only three times each day the exact time of maximum and minimum can not be 

 stated. 



From this table we see that the waves are not so large on the plateau as at Framheim, 

 but the nunrber of observations is too small to give a mean of real value. It is rmportant 

 to find how much earlier the phase of the waves is on the plateau than at the other 



