ke
and sweetened tea, I started with Charley to reconnoitre the country to
the westward. Our friendly stream not only turned to the north, but
afterwards to north-east and east-north-east; and though I had not
succeeded in leaving it from Reedy Brook--not having been able to cross
the lava streams of the basaltic table land--I now concluded, from the
nature of the pebbles, and sands of the creek which we had crossed last,
that the basalts and lavas had ceased, and that a passage to the westward
would be practicable.

I followed the Casuarina Creek up to its head, and called it "Big
Ant-hill Creek," in consequence of numerous gigantic strangely buttressed
structures of the white ant, which I had never seen of such a form, and
of so large a size.

The general course of the creek was north-north-west: for the first ten
miles it was without water, but its middle and upper course was well
provided with fine reedy holes, the constant supply of water in which was
indicated by Nymphaeas, and other aquatic plants. At its left side near
the junction I observed, as before mentioned, a coarse grained sandstone,
and, at less than a mile higher up, I found flint rock; and, wherever I
examined afterwards, the rocks proved to be coarse grained granite and
pegmatite, the decomposition of which formed a sandy soil on the slopes,
and clayey flats along the creek. The latter, however, were very limited.
The ant-hills were intimately connected with the rock, as the ants
derived their materials for building from the minute particles of clay
among the sand. The primitive rock was cut with deep gullies and ravines,
and several tributary creeks joined Big Ant-hill Creek from the primitive
side. The basaltic table land, which extended all along the right side of
the creek, formed steep slopes into its valley, and were generally topped
with loose basaltic boulders. The table land was highest near the creek,
and its drainage was not towards the creek, but to the south-west, into
the valley of lagoons. White quartz rock was observed in a few places on
the right side of the creek, where the primitive rock seemed to encroach
into the territory of the basalt; and felspathic porphyry formed probably
a dyke in the pegmatite, but was most evidently broken by the basalt.
Where the upper part of the creek formed a shallow watercourse, and
turned altogether into the primitive formation, a plain came down from
the west-north-west with a shallow watercourse,