January 6th, 1850.

Our passage to the Duchateau Isles, a distance of less than 400 miles,
has been protracted by the prevalence of light winds, although these were
generally favourable, or from the westward. Occasional calms, squalls,
and rain occurred, but the weather generally was finer than during the
South-East monsoon.

CLEARNESS OF THE ATMOSPHERE.

As an instance of the clearness of the atmosphere, so different from what
we had usually experienced during our former visit to these shores, it
may be mentioned, that on one occasion during a light breeze from the
north-west we clearly saw Mount Yule (10,046 feet high) and the summit of
Mount Owen Stanley, distant respectively, one hundred and twenty, and
eighty miles from the ship. On this occasion also we had a full view of
the whole of Mount Astrolabe, which although 3,824 feet in greatest
height, and appearing to D'Urville as he ran past to be the highest land
on this portion of the coast, is rendered quite insignificant by the
lofty though distant range behind. Mount Astrolabe differs in character
from any other of the New Guinea mountains seen by us, indicating a
different geological formation. The summit extends thirteen miles,
running parallel with the coastline and distant from it about eight
miles. Viewed from the south-westward the outline is regular, exhibiting
a series of nearly flat tops with slight interruptions, but from the
southward it appears as a succession of terraces or projecting cliffs,
precipitous in front near the summit, with a long steep slope below,
probably of debris, while the flat top slopes backwards with a very
gentle declivity. Owen Stanley Range again presented quite a different
aspect as seen on the occasion alluded to, when nearly one half of its