of a dry and technical character, three years being the time usually
allotted to a cruise. Australia, owing to the dangerous character of
its northern and eastern shores, has been the scene of numerous
surveys, among the latest of which was that by Captain Blackwood in
the _Fly_. One important result of this survey was the finding of a
passage through the great Barrier Reef for vessels navigating Torres
Strait; but as more than one passage was considered essential to the
safety of a route so much frequented, the _Rattlesnake_ was
commissioned, in September 1846, for a further survey, to be carried
on in what is called the Coral Sea, having New Guinea, the Louisiade
Archipelago, and the continent of Australia, as its boundaries.[3]

After some months spent in preliminary examination of different parts
of the Australian shores and seas, the _Rattlesnake_ sailed from
Sydney, at the end of April 1848, for the main object of her cruise.
She had the _Bramble_, a small schooner, as tender, and was
accompanied by the _Tam o' Shanter_, a vessel chartered for the
conveyance of Mr Kennedy's expedition, which was to land at Rockingham
Bay, 1200 miles to the northward, 'and explore the country to the
eastward of the dividing range, running along the north-east coast of
Australia, at a variable distance from the shore, and terminating at
Cape York.' Having assisted in landing this party, and arranged to
meet them at the head of Princess Charlotte's Bay, on their toilsome,
and, as it proved, disastrous overland journey, the ships pursued
their route, and soon commenced a series of triangulations, which were
continued without a break for more than 600 miles. The _Bramble_
waited ten days at the appointed rendezvous without seeing anything of
the overland expedition, which, as it afterwards appeared, did not
reach the same latitude until two months later, and then at a
considerable distance from the coast.