In order to render this passage perfectly intelligible it is necessary to observe that the island of Cocos lies in the latitude of 15 degrees 10 minutes south; and, according to Schovten’s account, is well inhabited, and well cultivated, abounding with all sorts of refreshments; but, at the same time, he describes the people as treacherous and base to the last degree. As for the islands of Horne, they lie nearly in the latitude of 15 degrees, are extremely fruitful, and inhabited by people of a kind and gentle disposition, who readily bestowed on the Hollanders whatever refreshments they could ask. It was no wonder, therefore, that, finding themselves thus distressed, Captain Tasman thought of repairing to these islands, where he was sure of obtaining refreshments, either by fair means or otherwise, which design, however, he did not think fit to put in execution.
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.
On the 16th we were in the latitude of 26 degrees 29 minutes south, and in the longitude of 199 degrees 32 minutes, the variation of the needle being 8 degrees. Here we are to observe that the eastern variation decreases, which is likewise very agreeable to Doctor Halley’s hypothesis; which, in few words, is this: that a certain large solid body contained within, and every way separated from the earth (as having its own proper motion), and being included like a kernel in its shell, revolves circularly from east to west, as the exterior earth revolves the contrary way in the diurnal motion, whence it is easy to explain the position of the four magnetical poles which he