France, at the diſtance of more than 700,000 toiſes ſouth, had been greater by twelve degrees than we found it near the coaſt of that land—a great difference when conſidered as ariſing merely from change of latitude.
The greateſt W. variation obſerved, was on the 3d of March. It was then 30½°, our lat. being 34° 30′ S. and long. 37° 45′ E. From that time it continued to decreaſe, till it became 0, in lat. 43° S. long. 129° E.; after which it paſſed to E. and continued to increaſe in proportion as we advanced eaſtward.
The W. variation of the magnetic needle, as obſerved till the period when it was the greateſt, had been more influenced by change of longitude than of latitude; though from that time, till we were under the meridian of Iſle de France, it appeared to depend much more upon change of latitude; for, from the point at which it had been the greateſt, till we paſſed under the meridian of Iſle de France, having changed our longitude by 17 degrees, and our latitude by 2½, the variation had been only 4°, though, by a change of latitude to 17 degrees further ſouth, the variation had been found 12° more than at Iſle de France.
The phoſporeſcence of the ſea, during this paſſage, had diminiſhed in an inverſe proportion to our diſtance from the land; ſo that a conſiderable
time
