372 
SCOTT'S LAST EXPEDITION 
[August 
southern temperatures at given latitudes. So far as 
these tables go they show the South Polar summer to be 
1 5 0 colder than the North Polar, but the South Polar 
winter 3 0 warmer than the North Polar, but of course this 
last figure would be completely altered if the observer 
were to winter on the Barrier. I fancy Amundsen will 
not concede those 3 0 ! ! 
From temperatures our lecturer turned to pressures and 
the upward turn of the gradient in high southern latitudes, 
as shown by the Discovery Expedition. This bears of 
course on the theory which places an anticyclone in the 
South Polar region. Lockyer's theories came under 
discussion ; a good many facts appear to support them. 
The westerly winds of the Roaring Forties are generally 
understood to be a succession of cyclones. Lockyer's hypo- 
thesis supposes that there are some eight or ten cyclones 
continually revolving at a rate of about io° of longitude 
a day, and he imagines them to extend from the 40th 
parallel to beyond the 60th, thus giving the strong 
westerly winds in the forties and easterly and southerly 
in 6o° to 70 0 . Beyond 70 0 there appears to be generally 
an irregular outpouring of cold air from the Polar area, 
with an easterly component significant of anticyclone 
conditions. 
Simpson evolved a new blizzard theory on this. He 
supposes the surface air intensely cooled over the con- 
tinental and Barrier areas, and the edge of this cold region 
lapped by warmer air from the southern limits of Lockyer's 
cyclones. This would produce a condition of unstable 
equilibrium, with great potentiality for movement. Since, 
