On the 8th of January, being in the latitude of
30 degrees 25 minutes south, and in the longitude of 192 degrees 20 minutes, we
observed the variation of the needle to be 90 degrees towards the east, and as
we had a high rolling sea from the south-west, I conjectured there could not be
any land hoped for on that side. On the 12th we found ourselves in 30 degrees 5
minutes south latitude, and in 195 degrees 27 minutes of longitude, where we
found the variation 9 degrees 30 minutes to the east, a rolling sea from the
south-east and from the south-west. It is very plain, from these observations,
that the position laid down by Dr. Halley, that the motion of the needle is not
governed by the poles of the world, but by other poles, which move round them,
is highly probable, for otherwise it is not easy to understand how the needle
came to have, as our author affirms it had, a variation of near 27 degrees to
the west, in the latitude of 45 degrees 47 minutes, and then gradually
decreasing till it had no variation at all; after which it turned east, in the
latitude of 42 degrees 37 minutes, and so continued increasing its variation
eastwardly to this time.
Early Australian Voyages, 1886, John Pinkerton |
