east, on
which we steered south-westward, and continued the same course until four
in the morning [THURSDAY 25 MARCH 1802]; when the largest Althorp Isle
being seen to the north-west, the ship was hove to, with her head
eastward; and at daylight, before making sail, the following bearings
were taken of the lands to the northward, but no part of Kangaroo Island
was visible.

Wedge I. (of Gambier's Isles), highest part, N. 641/2 deg. W.
Althorpe Isle, largest, distant 6 miles, N. 83 deg. to 78 W.
Cape Spencer, south point, N. 44 W.
Furthest extreme of the northern land, N. 44 E.

The wind fixed itself at south-east, and it took us two days to work back
against it as far as Troubridge Hill [SATURDAY 27 MARCH 1802]. The shore
is generally low and sandy; but with the exception of one very low point,
it may be approached within two miles. Many tacks were made in these two
days from the northern land across to Kangaroo Island, and gave
opportunities of sounding the intermediate strait. From 45 fathoms, in
the middle of the western entrance, the depth diminished quickly to 25,
then more slowly to 20 after which it is irregular between 12 and 20
fathoms, as far as the mouth of the second inlet. Of the two sides, that
of Kangaroo Island is much the deepest; but there is no danger in any
part to prevent a ship passing through the strait with perfect
confidence, and the average width is twenty-three miles. It was named
INVESTIGATOR'S STRAIT, after the ship. The bottom is mostly broken
shells, mixed with sand, gravel or coral, and appeared to hold well.

From two amplitudes taken to the north-north-west of Point Marsden, and
near the middle of the strait, the variation was 1 deg. 49' east; the ship's
head being south-south-east in one case, and north-east-by-north in the
other. The true variation deduced from these, is 3 deg. 20' east; which is 1 deg.
7' greater than at Cape Spencer, and 0 deg. 53' less than at the anchorage
near Kangaroo Head.

At noon of the 27th, the eastern wind died away; and we dropped a kedge
anchor in 15 fathoms, about two miles from Point Marsden, where the
following observations and bearings were taken.

Latitude, observed to the north, 35 deg. 31' 38"
Longitude by time keepers, 137 42
Kangaroo I., furthest western extreme, S. 82 W.
do., Point Marsden, west side, S. 26 W.
do., innermost head up Ne