to the Strait of Magellan, 



35 



weed on the surface. This admirable spot is unnoticed by all 

 former navigators ; only Sarmiento mentions iiis having an- 

 chored in that quarter, in a place which he called Narrow Har^ 

 hour. We examined and made a draught of the port, but 

 found both wind and sea too violent to suffer us to continue our 

 Toyage ; we therefore passed the night in a small cove on its west 

 side. We observed the ebb and tiow of the tide, but were sur- 

 prised to see that, during both, the current on the outside con- 

 tinued still to the SE. In order to make the best use of our 

 time, we measured on the shore a base of 96 fathoms, which was 

 as much as the ground would allow ; and, by angles measured from 

 the extremities to objects at a distance, we obtained another base 

 of 378 fathoms, by which we calculated the bearings and dis- 

 tances of several remote objects, to carry on the series of trian- 

 gles necessary for our survey of the strait. 



The gale still continuing, next morning we had, luckily, a 

 short view of the sun, by which and our chronometer (Arnold's) 

 we found the longitude of Cape Monday W. from Cape Vir- 

 gins perfectly to coincide with that previously calculated. We 

 at the same time observed the variation of the rnagnetic needle^ 

 by a method not generally known, but first practised by the 

 eminent French astronomers Borda and Verdun. Two ob- 

 servers took at the same time, the one the sun's altitude, and 

 the other his angular distance from a remarkable object on the 

 north coast, of which the situation had been v/ell ascertained. 

 We then measured the angular elevation of that object above 

 the horizon, and carefully marked its bearing by the compass: 

 we next, by the complements of both altitudes and the distance, 

 found the angle at the zenith formed by the verticals. By 

 the sun's altitude and his declination, and the latitude, we found 

 the azimuth, from which subtracting the first angle found, the 

 remainder gave the true bearing of the object observed on the 

 land. By this process, the variation of the needle came out to 

 be 22^ 43' 56' E. of N. 



The wind fell about 2 p.m. and we proceeded on our voyage. 

 Rowing about two miles, we landed on a small island, to take 

 the bearings and intersections of several objects before observed. 

 The wind suffered us only to gain a spacious bay to the east of 

 Cape San Ildefonso, called by the English Cape Upright, At 

 the east side of the mouth of the bay is a triangular island, one 

 mile and a half in length NE. by N. and SW. by S. ; having be- 

 tween it and the main of Tierra del Fuego a channel one mile 

 and a half broad, and three miles in depth, to the bottom of the 

 bay. The bay is in breadth two leagues, and in the bottom, 

 towards the east side, is a channel, running up S. bv E. among 

 the mountains. Between the island and the east coast we 



F 2 



