Travel Reference
In-Depth Information
the edible birds' nests of Aru are chiefly obtained. All my informants stated that the two
southern rivers are larger than Watelai.
The whole of Aru is low, but by no means so flat as it has been represented, or as it ap-
pears from the sea. Most of it is dry rocky ground, with a somewhat undulating surface,
rising here and there into abrupt hillocks, or cut into steep and narrow ravines. Except the
patches of swamp which are found at the mouths of most of the small rivers, there is no ab-
solutely level ground, although the greatest elevation is probably not more than two hundred
feet. The rock which everywhere appears in the ravines and brooks is a coralline limestone,
in some places soft and pliable, in others so hard and crystalline as to resemble our moun-
tain limestone.
The small islands which surround the central mass are very numerous; but most of them
are on the east side, where they form a fringe, often extending ten or fifteen miles from the
main islands. On the west there are very few, Wamma and Pulo Babi being the chief, with
Ougia and Wassia at the north-west extremity. On the east side the sea is everywhere shal-
low, and full of coral; and it is here that the pearl-shells are found which form one of the
chief staples of Aru trade. All the islands are covered with a dense and very lofty forest.
The physical features here described are of peculiar interest, and, as far as I am aware, are
to some extent unique; for I have been unable to find any other record of an island of the
size of Aru crossed by channels which exactly resemble true rivers. How these channels ori-
ginated were a complete puzzle to me, till, after a long consideration of the whole of the nat-
ural phenomena presented by these islands, I arrived at a conclusion which I will now en-
deavour to explain. There are three ways in which we may conceive islands which are not
volcanic to have been formed, or to have been reduced to their present condition,—by elev-
ation, by subsidence, or by separation from a continent or larger island. The existence of
coral rock, or of raised beaches far inland, indicates recent elevation; lagoon coral-islands,
and such as have barrier or encircling reefs, have suffered subsidence; while our own is-
lands, whose productions are entirely those of the adjacent continent, have been separated
from it. Now the Aru Islands are all coral rock, and the adjacent sea is shallow and full of
coral; it is therefore evident that they have been elevated from beneath the ocean at a not
very distant epoch. But if we suppose that elevation to be the first and only cause of their
present condition, we shall find ourselves quite unable to explain the curious river-channels
which divide them. Fissures during upheaval would not produce the regular width, the regu-
lar depth, or the winding curves which characterise them; and the action of tides and cur-
rents during their elevation might form straits of irregular width and depth, but not the river-
like channels which actually exist. If, again, we suppose the last movement to have been one
