The scientific results of the _Roebuck's_ voyage were, chiefly on these
accounts, of no great importance, judged by the standard of such work
to-day; but, with the state of nautical science at the time, not much was
to be expected in the way of accurate surveying.
When Dampier set out to explore the coast of New Holland, what charts,
what instruments, what scientific knowledge and equipment, had he for the
work?
Dampier's time was distinctively an intermediate period. Little more than
a century had elapsed since Gerard Mercator's chart was published, and
Edward Wright had taught its true principles, and about half a century
before the voyage of the _Roebuck_ such improvements as Gunter's
application of logarithms to nautical calculations, middle latitude
sailing, and the measurement of a degree on the meridian were introduced.
Hadley's quadrant came thirty years after Dampier, who must have used
Davis' instrument, then about ninety years old. Davis' work on navigation,
with Wright's chart showing the northern extremity of Australia, and
Addison's _Arithmetical Navigation_ (1625) were, no doubt, text-books on
board the _Roebuck_. Longitude by chronometer was to come half a century
after Dampier was in his grave, and such charts as he possessed did little
more than indicate the existence of Terra Australis. The Portuguese,
Spanish, and Dutch maps were not easy for Englishmen to procure, and all
that Dampier has to say on the matter is:--
"But in the draught that I had of this coast, which was Tasman's,
it was laid down in 19 degrees, and the shore is laid down as
joining in one body or continent, with some openings appearing
like rivers, and not like islands, as really they are.
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