318 ERRATIC BOULDERS. 



furthest from the Pole, surveyed during the voy- 

 ages of the Adventure and Beagle, is in lat. 46° 

 50', in the Gulf of Penas. It is 15 miles long, and 

 in one part 7 broad, and descends to the seacoast. 

 But even a few miles northward of this glacier, in 

 the Laguna de San Rafael, some Spanish mission- 

 aries* encountered " many icebergs, some great, 

 some small, and others middle-sized," in a narrow 

 arm of the sea, on the 22d of the month correspond- 

 ing with our June, and in a latitude corresponding 

 with that of the Lake of Geneva ! 



In Europe, the most southern glacier which 

 comes down to the sea is met with, according to 

 Von Buch, on the coast of Norway, in lat. 67°. 

 Now this is more than 20° of latitude, or 1230 miles, 

 nearer the pole than the Laguna de San Rafael. 

 The position of the glaciers at this place and in the 

 Gulf of Penas may be put even in a more striking 

 point of view, for they descend to the seacoast 

 within 7^° of latitude, or 450 miles, of a harbour, 

 where three species of Oliva, a Voluta, and a 

 Terebra are the commonest shells, within less than 

 9° from where palms grow, within 4^° of a region 

 where the jaguar and puma range over the plains, 

 less than 2^° from arborescent grasses, and (looking 

 to the westward in the same hemisphere) less than 

 2° from orchideous parasites, and within a single 

 degree of tree-fems ! 



These facts are of high geological interest with 

 respect to the climate of the northern hemisphere, 

 at the period when boulders were transported. I 

 will not here detail how simply the theory of ice- 

 bergs being charged with fragments of rock ex- 

 plains the origin and position of the gigantic boul- 

 ders of eastern Tierra del Fuego, on the high plain 

 of Santa Cruz, and on the island of Chiloe. In 

 * Agiieros, Desc. Hist, de Chiloe, p. 227. 



