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

Jan. 1827. mount sakmiento. 27 and excellent is his description. It is also mentioned in the account of Cordova's voyage.* The peculiar shape of its summit as seen from the north would suggest the probability of its being a volcano, but we never observed any indication of its activity. Its volcanic form is perhaps accidental, for, seen from the westward, its summit no longer resembles a crater. From the geological character of the surrounding rocks its for- mation would seem to be of slate. It is in a range of mountains rising generally two or three thousand feet above the sea; but at the N.E. end of the range are some, at least four thousand feet high. The height of the "Snowy Volcano," or as we have called it. Mount Sarmiento,-|- was found, by trigonometrical measure- ment, to be six thousand eight hundred feetj above the level • Ultimo Viape, p. 120. t Fioiu an attentive perusal of the voyage of Magalhaens, I have lately been led to tliink that this is the mountain which IMagalhaens called Roldan's Boll. Sarmicnto has, however, assigned that name to a moun- tain at the back of his Bay of Campana, which will be noticed in it's proper place. The name of Mount Sarmiento was too long, and too well established with us, or I should have restored the name bestowed upon it by Magalhaens. Herrera, in his Descripcion de las Indias Occidentales, cap.xxiii, notices the "Campana de Roldan" as a great mountain in the midst of the entrance of a channel ; they gave it this nam.e (Cam- pana de Roldan) because one of Magalhaens's companions, named Roldan, an artillery officer, went to examine it. " Y la Canjpana de Roldan una Pena grande en medio al principio de un canal : dieron le este nombre por(jue la fue a reconocer unodelos compaueros de Magallanes llamado Roldan que era artillero." I By angular measurement, with a theodolite, from the tent, the base being by diff. of lat. 297,863 feet, and allow- ing ^ of the intercepted arc for terrestrial refraction . . 6,864 feet. By angular measure with sextant (index error, dip, and ^'^ of the intercepted arc being allowed) the base being 290,074feet 7,237 By angular measurement, with a theodolite, from Warp Bay, by Lieuts. Skj'ring and Graves 6,800 Mean 6,967 feet, but as the last observation, from the angle of elevation being greater, was more likely to be correct, 6,800 feet is considered to be its elevation.