THE LLANOS. 107 



at which thej were on their mules ; yet, in the midst of 

 this apparent calm, whirls of dust incessantly arose, 

 driven on by small currents of air which glided over the 

 surface of the ground, and were occasioned by the differ, 

 ence of temperature between the naked sand and the 

 spots covered with grass. These sand-winds augmented 

 the suffocating heat of the air. Every grain of quartz, 

 hotter than the surrounding air, radiated heat in all 

 directions ; and it was difficult for Humboldt to observe 

 the temperature of the atmosphere, owing to the particles 

 of sand striking against the bulb of the thermometer. 

 All around the plains seemed to ascend to the sky, and 

 the vast and profound solitude appeared like an ocean 

 covered with sea-weed. The horizon in some parts was 

 clear and distinct, in other parts it appeared undulating, 

 sinuous, and as if striped. The earth there was con- 

 founded with the sky. Through the dry mist and strata 

 of vapour the trunks of palm-trees were seen from afar, 

 stripped of their foliage and their verdant summits, and 

 looking like the masts of a ship descried upon the hori- 

 zon. There was something awful, as well as sad and 

 gloomy, in the uniform aspect of these steppes. Every 

 thing seemed motionless; scarcely did a small cloud, 

 passing across the zenith, and denoting the approach of 

 the rainy season, cast its shadow on the earth. 



The chief characteristic of these steppes was the abso- 

 lute want of hills and inequalities — the perfect level of 

 every part of the soil. Often within a distance of thirty 

 square leagues there was not an eminence of a foot high. 



After having passed two nights on horseback, and 

 sought in vain, by day, for some shelter from the heat 

 of the sun beneath the tufts of the palm-trees, they 



