ANNOTATIONS AND ADDITIONS. 35 



singular aspect of this sea-like desert plain. As far as the 

 eye can reach, it can hardly rest on a single object a few 

 inches high. If it were not that the state of the lowest 

 strata of the atmosphere, and the consequent changes of 

 refraction, render the horizon continually indeterminate and 

 undulating, altitudes of the sun might be taken with the 

 sextant from the margin of the plain as well as from the 

 horizon at sea. This great horizontality of the former sea 

 bottom makes the "banks" more striking. They are 

 broken strata which rise abruptly from two to three feet above 

 the surrounding rock, and extend uniformly over a length 

 of from 40 to 48 English geographical miles. The small 

 streams of the Steppes take their rise on these banks. 



In passing through the Llanos of.Barcelona, on our return 

 from the Rio Negro, we found frequent traces of earth- 

 quakes. Instead of the banks standing higher than the 

 surrounding rock, we found here solitary strata of gypsum 

 from 3 to 4 toises (19 to 25 English feet) lower. Partner 

 to the west, near the junction of the Caura with the Orinoco, 

 and to the east of the mission of S. Pedro de Alcantara, an 

 extensive tract of dense forest sank down in an earthquake 

 in 1790, and a lake was formed of more than 300 toises 

 (1918 English feet) diameter. The tall trees (Desmanthus, 

 Hymenseas, and Malpighias) long retained their foliage and 

 verdure under the water. 



( 3 ) p. 2. "We seem to see before us a shoreless ocean" 



The prospect of the distant Steppe is still more striking, 



when the spectator has been long accustomed in the dense 



