APPEN^DIX. 



place the methods adopted by the officers of the Beagle, in the exa- 

 mination of a wild sea- coast — such, for example, as that of the 

 south-western part of Tierra del Fuego. 



On that coast the weather was so continually bad, there was so 

 much swell, and the water near the steep precipitous shores always 

 so deep, that anchorage (except in harbours) was impracticable : 

 boats were seldom able to assist (while under way), and the bearing 

 compass, though particularly good, and well placed, was of very little 

 use : it was therefore never trusted in important bearings. Another 

 impediment, and not a slight one, was the current ; which set irre- 

 gularly from one knot to three knots an hour, along the shore. 



But there are seldom evils, unbalanced by remedies. The stormy 

 and desolate shores of Tierra del Fuego are broken into numerous 

 islands, about which anchorages are abundant, and they are excel- 

 lent, when once a vessel is in them. To find, and enter, or leave 

 them in most instances, was troublesome, and often dangerous. But, 

 with the help of those havens, and the distinct marks afforded by a 

 high rocky shore ; and by the sharp peaks of more distant heights^ 

 a correct survey was effected. 



Beginning at the western extreme, near Cape Pillar (because the 

 prevailing w^inds are westerly, and the current sets to the eastward),, 

 our first object was to find a safe harbour in which to secure the 

 ship. There we made observations for latitude, time, and true bear- 

 ing ; on the tides, and magnetism. We also made a plan of the 

 harbour and its environs ; and triangulations, including all the 

 visible heights, and more remarkable features of the coast, so far as 

 it could be clearly distinguished from the summits of the highest 

 hills near the harbour. Upon these summits a good theodolite was 

 used, which was set, invariably, to a well-defined mark, near the 

 observatory ; from which mark the true bearings of the stations 

 on the summits of the hills were ascertained by observations of the 

 sun made with a theodolite. 



Many leagues of exposed, and difficult coast, were looked down 

 upon, in this manner ; and, at the least, their exact bearings from 

 one fixed spot ascertained. But if more than one height afforded a 

 round of angles with the theodoHte, and the position of each of 

 those heights was accurately known by triangulation depending 

 upon a base measured at the harbour, then the positions of various 

 other hills or marks were ascertained ; and so much easier became 



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