ular
ice-wall is from thirty to three hundred feet in height. Behind this
wall are vast ice-fields, and beyond these immense plateaus of ice
having an elevation of six thousand to twelve thousand feet where fierce
winds and a biting cold prevail. On these elevated plains the
thermometer stands in the middle of summer sometimes as low as forty
degrees below zero.

Great fields of ice and huge icebergs cover the sea in all directions
and in winter extend far beyond the antarctic circle. In these regions
the ice forming on the surface of the ocean attains a thickness varying
from five to seventeen feet. Long ranges of snow-clad and ice-mailed
mountains are found with ermined peaks towering from ten thousand to
fifteen thousand feet in height.

A long winter night, with its intense darkness relieved at times by the
light of the moon and brilliant chromatic displays of the aurora
australis, succeeds a day of perpetual sunshine. All these are on such a
scale of sublimity that no pen can adequately describe nor brush portray
them. Nowhere else on the face of the globe does there exist such a wide
expanse of utter desolation. Yet an undefined attraction lures bold men
to fathom the mysteries of these forbidding regions. Dating from 1772,
many exploring expeditions have visited the south polar regions in the
interests of science.

The compass is the mariner's guide across the trackless ocean, and it is
essential to find out everything possible about that mysterious agent,
magnetism, which directs the compass needle by its attractive force. The
earth itself is a huge magnet with positive and negative poles. The
poised needle of the compass maintains its relative position because of
the magnetic poles of the earth, one located in the north polar regions,
on the western side of the peninsula of Boothia, and the other in the
south polar regions, on Victoria Land. Except in a few localities the
compass needle does not point due north and south--that is, toward the
real poles of the earth, but toward the magnetic poles. And these
magnetic poles are ever shifting, as is shown by the changing direction
of the compass needle, which year by year increases or decreases its
deviation from true north and south.

It is necessary to chart the variations of the magnetic needle for the
use of the navigator. To observe the deviations and to locate the south
magnetic pole have been the chief objects of south polar expeditions for
several year