Page:Tasman A Forgotten Navigator.djvu/15

 proposed that they should keep to the more northerly parallel of 44° South until they had passed the 129th meridian, and then make for the parallel of 40° South, and, if no land was then seen, to keep in that parallel until 180° East was reached, and then steer North. It was therefore resolved to steer North-east until 44° South.

As they get more northerly, the westerly gales lulled, but the sea ran high from the southward, and they opined, therefore, that there was no large tract of land in that direction. On November 17th, forty days out, their latitude was 44° 15' South, and their longitude 126° East. They found the compass variation 8° West. That is, the north point of the compass needle is drawn 8 degrees west of the true north. The magnetic pole has so changed its position in two and a half centuries that the variation in this locality is now 2° West. The variation of the compass needle was familiar enough to the navigators of Tasman's time, but to Columbus, who first observed the aberration, it occasioned great uneasiness, and much terror to his officers and crew. They had now passed Cape Leewin, and were abreast the Great Australian Bight. It shows the accuracy of Tasman's navigation when he mentions that he must now have passed that part of the South land already known, or at least as far eastward as the land which Peter Nuyts had visited fifteen years before.

That night they lay to, and at daylight sailed again eastward. On November 22nd, if Tasman had steered North about 50 miles, he would have discovered the Kangaroo Island of South Australia.

Tasman is here alarmed at the eccentricities of his compass, which swings four points, or 45 degrees. He imagines that there must be loadstones in the vicinity. Those of us who have had the pleasure of reading the voyages of the celebrated navigator, Sinbad, may remember that on one occasion his ship was wrecked when passing a distant mountain of such magnetic power that it drew every iron bolt from the sides of Sinbads vessel, causing a general collapse.

Before the laws of magnetism were so well understood as they now are, a modified idea of a similar nature obtained credence, not only with seamen, but with minds of scientific order.

Without going to the extreme view given in Sinbad's history, as to a magnetic force acting on the ironwork of a vessel at sea, it was, and is still, a belief that there are various shores throughout the world, the rocks of which are so full of magnetic iron as to seriously interfere with the compasses of passing vessels.

The Admiralty charts call attention to such localities. The northern shores of the Gulf of Finland are of such a nature, and also the northern coast of the Gulf of St. Lawrence has in the Admiralty "Books of Direction" the same physical character.