Narrative of the surveying voyages of his majesty's ships Adventure and Beagle (vol.1): between the years 1826 and 1836 : describing their examination of the southern shores of South America, and the Beagles's circumnavigation of the globe

April 1830. compasses affected — cape horn. 431 wind failed entirely. During the night we had a breeze that would have carried us down to the latter spot, but wishing to see, and take bearings of the land as I went, I did not profit by it ; and in the morning was baffled with light airs and a current setting to the northward. " 17th. During the early part of the day we had light variable winds, scarcely sufficient to help us against the cur- rent which seemed to set constantly into the bay, from the sea, at the rate of about one knot an hour. The manner in which our compasses were affected in this bay was remarkable ; all of them being extremely sluggish, and, unless continually shaken, they did not show the proper magnetic bearings, or agree together, nearer than two points. I sharpened the centres with much care, and examined the agate caps, without improving the results. The compasses considered the best in other places, were here as bad as the worst ; an excellent one, upon Alexan- der's principle, with central jimbals, being nearly viseless. In trying the compasses on shore, the heavy cards with large needles had been less affected by local influence than light deli- cate cards of Kater : the heavy ones having averaged 24° vari- ation along the whole coast, though Kater's differed in some places as much as from 19° to 28 ° ; agreeing nearly with each other, but not with Gilbert's or Alexander's compasses, in both of which were cards comparatively heavy. " We passed much too close to West Cape, but having fortunately cleared it, ran along the land before a moderate breeze, and rounded Cape Spencer at dusk. The weather was so thick that Cape Horn could not be seen, and we mistook the former for the famous cape ; especially as, in that view, the lower part of Cape Spencer looked like the head of a double-horned rhinoceros : but as we drew nearer. Cape Horn appeared. The wind failed as we entered the Bay of St. Francis, and left us to the alternative of anchoring in deep water, or driving about with the current : we therefore anchored off San Joachim Cove, near the Seal Rock. The night proved fine, so we lay quietly till next moi-ning, and then made sail to a breeze from the northward and anchored in San Martin