rom the seaward cliffs to an elevation of one thousand five
hundred feet. Several small islands were visible close to a shore
fringed by numerous large bergs.

"At 10 P.M. on January 20, our progress to the west was stopped by a
fleet of bergs off the mainland and an extensive field of berg-laden
pack-ice, trending to the north and north-east. Adelie Land could be
traced continuing to the west. Where it disappeared from view there was
the appearance of a barrier-formation, suggestive of shelf-ice,
running in a northerly direction. Skirting the pack-ice on a north and
north-west course, we observed the same appearance from the crow's-nest
on January 21 and 22."

The stretch of open, navigable, coastal water to the north of Adelie
Land, barred by the Mertz Glacier on the east and delimited on the west
by more or less compact ice, has been named the D'Urville Sea. We found
subsequently that its freedom from obstruction by ice is due to the
persistent gales which set off the land in that locality. To the north,
pack-ice in variable amount is encountered before reaching the wide open
ocean.

The existence of such a "barrier-formation,"** as indicated above,
probably resting on a line of reef similar to the one near Cape
Discovery, would account for the presence of this ice-field in
practically the same position as it was seen by D'Urville in 1840.

** An analysis of the data derived from the later voyages of the
'Aurora' makes it practically certain that there is a permanent obstacle
to the westerly drift of the pack-ice in longitude 137 degrees E. There
is, however, some uncertainty as to the cause of this blockage. An
alternative explanation is advanced, namely, that within the area
of comparatively shallow water, large bergs are entrapped, and these
entangle the drifting pack-ice.

At a distance, large bergs would be undistinguishable from shelf-ice,
appearances of which were reported above.

Quoting further: "We were unable to see any trace of the high land
reported by the United States Squadron (1840) as lying to the west and
south beyond the compact ice.

"At 1.30 A.M. on the 23rd the pack-ice was seen to trend to the
south-west. After steaming west for twenty-five miles, we stood south in
longitude 182 degrees 30' E, shortly afterwards passing over the charted
position of Cote Clarie. The water here was clear of pack-ice, but
studded with bergs of immense size. The great barrier which the French
ships