30 seconds; it comprises a
large part of Sturt Plains, with soil formed of a fine lacustrine
deposit, the valleys of the Roper filled with a luxuriant tropical
vegetation, and thence to the Adelaide River and the sea-coast.

On visiting Hergott Springs, Mr. Waterhouse learnt that Mr. Burtt, whose
station* is only a few miles distant, in opening these springs discovered
some fossil bones, casts of which were forwarded to Professor Owen, who
pronounced them to be the remains of a gigantic extinct marsupial, named
Diprotodon Australis. (* Hergott Springs were only discovered and named
by Stuart three years before, yet we now find a station close by them.
The explorer is not far ahead of his fellow-colonists, as is well
remarked by the Edinburgh Review for July, 1862: "Australian occupation
has kept close on the heels of Australian discovery.") Bones of this
animal have also been found in a newer tertiary formation in New South
Wales. Mr. Waterhouse considers that a great tertiary drift extends over
this part of the country, obscuring and concealing at no great depth
below the surface many springs, which may hereafter be discovered as the
country becomes better known.

The Louden Spa is a hot spring arising out of a small hillock, and
proceeds from the fissures of volcanic rock. This water is medicinal, but
not disagreeable to the taste: the damper made with it was very light,
and tasted like soda-bread.

In his remarks on the second division Mr. Waterhouse states much that is
valuable. He estimates the height of Mount Hay at two thousand feet,
regarding it as the highest point of the McDonnell Range, which is the
natural centre of this part of the continent. Mr. Waterhouse only saw
Chambers Pillar from a distance, but he had an opportunity of examining a
smaller hill of the same character, and found it to be composed of a soft
loose argillaceous rock, at the top of which was a thin stratum of a hard
siliceous rock, much broken up. "The isolated hills appear to have been
at some remote period connected, but from the soft and loose nature of
the lower rock meeting with the action of water, had arisen a succession
of landslips. These have been washed away and others have followed in
their turn; the upper rock, from being undermined, has fallen down and
broken up, supplying the peculiar siliceous stones so widely distributed
on parts of the surface of the country."

The vegetation of this district is poor; the myall is scar