1914-15.] Meteorological See-Saw over Antarctic Seas. 205 
much to its interest. The mean seasonal values for M‘Murdo Sound and 
Laurie Island, South Orkneys, are as follows : — 
______ 
Months. 
Barometer, Mean 
corrected to 0° C., 
Sea-Level, and 
I. at. 4y. 
Temperature in 
Degrees Centigrade. 
Wind Velocity, Metres 
per Second. 
M‘Murdo 
Sound. 
South 
Orkneys. 
M^Murdo 
Sound. 
South 
Orkneys. 
M‘Murdo 
Sound. 
South 
Orkneys. 
Evange- 
lists’ 
Island. 
1 (Beaufort.) 
Dec., Jan., Feb. 
Mar., ApL, May 
June, July, Aug. 
Sept., Oct., Nov. 
mm. 
745-6 
44-7 
40- 7 
41- 9 
mm. 
744-5 
43- 2 
44- 0 
42-3 
- 6-1 
-20-7 
-25-6 
-18-5 
- 0-4 
- 4-5 
- 10-0 
- 5-1 
5- 5 
7-1 
7-4 
6- 2 
1 
4-3 i 4-8 
6-6 ' 4-9 
6-4 4-8 
4-9 4-7 
The salient features of the see-saw are shown in Table I, in which the 
departures from the normals in the barometric pressure, temperature, and 
wind velocity are given for each seasonal three-monthly group. Baro- 
metric pressure is given in millimetres, temperature in centigrade, and 
wind velocity in metres per second. 
The mean wind velocity on the Beaufort scale as recorded at 
Evangelists’ Island at the Pacific entrance to the Straits of Magellan 
(lat. 52° 24' S., long. 75° 06' W.) is also shown. Records from this station 
are of particular interest owing to its position, about midway between the 
South Pacific high-pressure area and the Bellingshausen Sea low-pressure 
area. As we have shown,^ there exists over the South Pacific a well-marked 
see-saw of pressure, temperature, and wind velocity just as marked — even 
more so, in some respects — as the one existing between the Weddell Sea and 
Ross Sea areas. Every confidence attaches to the uniformity of the wind 
data, since the observations throughout the four years under review were 
made by the same observer, Sehor Eduardo Williams, keeper of the light- 
house, in what is one of the most inclement regions on the surface of the 
globe. The hours of observation were 8 a.m., 2 p.m., and 9 p.m. during the 
seasons of 1902, 1903, and 1904, and 7 a.m., 2 p.m., and 9 p.m. during 1911 
and 1912.t 
* “ Meteorology in Weddell Quadrant during 1909,” Scot. Geog. Jour., vol. xxvi, p. 413. 
t Data till February 1904 from tlie Anuario del Servicio Meteorologico de la Direccion del 
Territorio Maritimo, 1902, 1903, and 1904, and for 1911 and 1912 from the Anuario Meteoro- 
logico de Chile, by Dr Walter Knoclie, Director. 
[Table I 
