752 LOUIS AGASSIZ. 



which stand the ruins of a Spanish fort, near 

 the fishermen's huts of San Vicente, which 

 lies between Concepcion Bay and the Bay of 

 Aranco. Whether the polished surface is the 

 work of a glacier descending from the Andes 

 to the sea-shore or not, I have not yet been 

 able to determine. I find no volcanic pebbles 

 or boulders in this vicinity, which, after my 

 experience in San Carlos, I should expect all 

 along the shore, if the glaciers of the Andes 

 had descended to the level of the ocean, in 

 this part of the country. The erratics here 

 have the character of those observed farther 

 south. It is true the furrows and scratches 

 of this polished surface run mainly from east 

 to west ; but there are some crossing the main 

 trend, at angles ranging from 20° to 30°, and 

 running S. E. N. W. Moreover, the magnetic 

 variation is 18° 3' at Talcahuano April 23d, 

 the true meridian bearing to the right of the 

 magnetic. I shall soon know what to make 

 of this, as I start to-morrow for the interior, 

 to go to Santiago and join the ship again at 

 Valparaiso. I have hired a private carriage, 

 to be able to stop whenever I wish so to do. 

 I also take a small seine to fish for fresh water 

 fishes in the many streams intervening be- 

 tween this place and Valparaiso. The trend 



