Jan. 1830. compass affected — drawings. 383 



ing to make no further use of a compass in this place ; and as 

 Lieutenant Skyring might have been deceived in his bearings 

 from a similar cause, I hoped to procure a round of angles, with 

 a theodolite set to a true bearing, which might be serviceable 

 for his work, as well as my own. Many pieces of the stone, 

 from different heights, were brought down ; and in most of 

 them were traces of metal. 



" The peaked top of this mountain is a mere heap of loose 

 stones of all sizes. Whether the rock has been shattered in this 

 manner by frost, by volcanic fire, or by lightning, I cannot 

 tell ; but I should think, from its appearance, by all three. 

 Many of the stones are vitrified, and many are porous, like 

 pumice-stones, although not so light. 



" 20th. I again went up Mount Skyring, taking a theodolite 

 with me ; and as the day was perfectly clear, and free from 

 clouds, every point of land was visible, which can at any time 

 be seen from that summit. Mount Sarmiento appeared in all 

 its grandeur, towering above the other mountains to at least 

 twice their height, and entirely covered with snow. Having set 

 the theodolite to a painted post, fixed on shore near the Beagle 

 (five miles distant), from which I had previously obtained the 

 exact astronomical bearing of the spot on which the theodolite 

 was placed; I obtained a most satisfactory round of angles, 

 including most of the remarkable peaks, islands, and capes, 

 within a range of forty miles from the mountain. The day was 

 so fine, that it was not cold on the height, nor was there any 

 wind to disturb the adjustment of the instrument. 



This business being completed, I returned on board with 

 Mr. Wilson, who, during the time I was on the height, made 

 some very good sketches. Even at this early period his draw- 

 ings were becoming a valuable addition to the gleanings of our 

 cruise, and their number increased fast ; for he took much 

 pains with them, and produced not only good drawings, but 

 most accurate delineations of the coast. 



" 21st. Fine weather for this climate. Mr. Murray returned 

 in the whale-boat, having had a successful trip. 



" By shooting and fishing we obtained frequent change of 



