211 
1914 - 15 .] Meteorological See-Saw over Antarctic Seas. 
At M‘Murdo Sound pressure is above the mean from November to 
April, reaching the annual maximum in December, and during the months 
May to October it is below the average, reaching the minimum in October. 
At the South Orkneys there is a pronounced maximum in June, July, 
and August when pressure at M‘Murdo Sound is at its seasonal minimum ; 
and there is a secondary maximum in December. The period of mini- 
mum pressure embraces the five months January to May ; in October 
also the pressure is slightly below the normal, and the most prominent 
minimum occurs in November. In the South Pacific area represented 
by the French and Belgian data, the maximum for the year, as at the 
other two stations, falls in December, and the minimum — which is 
very pronounced — from February to April. As at the South Orkneys, 
pressure is in excess of the normal in June and July. In summer 
— November to January — the departure is in harmony with that at 
M‘Murdo Sound. 
The temperature values show that the mean is above the annual average 
from November to March at M'Murdo Sound, from October to March in 
the South Pacific area, and from October to April at the South Orkneys, 
the prolongation of the warm period at this station being due to the 
absence of ice in the seas surrounding these islands until well on in 
autumn. At M‘Murdo Sound, as already pointed out, the values from 
April to September show little variation, due to the causes referred to. 
Temperature rises sharply in November, and continues rising into 
December, when the annual maximum is reached. An appreciable fall 
occurs in February, and in March and April continental conditions are 
asserting themselves, only to be checked in May. At the South Orkneys 
the maximum, as is usually the case at island stations, occurs in February, 
and there is only a slight fall in March. 
The wind velocity is at its annual minimum in summer — November to 
January — both at the South Orkneys and at M‘Murdo Sound. At the 
former station there is a distinct double period with maxima at the 
equinoxes and minima at the solstices. The maximum at M‘Murdo Sound 
is reached in March and the minimum in January, but the stormy period 
here begins in February and terminates in August, whereas at the South 
Orkneys September has the highest mean velocity of the year, and October 
is also a stormy month. It is not necessary to amplify details, since the 
general features of Antarctic meteorology have been already treated in 
papers published some years ago. The additional material since accumu- 
lated does not modify to any appreciable extent the conclusions then 
arrived at. 
