108 AFLOAT UPON THE LLANOS. 



the savannas of the Apurc, the temperature of the clay, as 

 we have before stated, often rises above 100° Fahr., and 

 this is but little lessened by the shades of night. When 

 the sun was obscured by clouds which overcast the heav- 

 ens, thus impeding radiation from the earth, the heat 

 became even more oppressive. 



The Rio Clarito, down whose course we vrere floating, 

 has its waters, as the name of the river signifies, beauti- 

 fully clear ; yet the stream appears of an inky color, re- 

 flecting light so admirably that we could see our image as 

 in a mirror, Notwithstanding the presence of a coloring 

 principle, imparted to the waters by percolation through 

 the thick masses of vegetable matter which cover the earth, 

 these aguas negras, or black waters, as they are called, 

 had to us an agreeable, although a peculiar, taste, and 

 were preferable to the white, muddy mixtures of the Pao, 

 Apure, and Orinoco, such as we were compelled to use for 

 so long a time. It must be borne in mind that springs in 

 the interior are of rare occurrence; we travelled from 

 Valencia to Para, a distance of over three thousand miles, 

 without as much as once quenching our thirst with a more 

 refreshing beverage than the impure and tepid water ob- 

 tained from the rivers we navigated. It is a remarkable 

 phenomenon that the same district of country should give 

 rise to streams, some of whose waters are white and 

 thick with sediment, while others are black, yet admirably 

 clear. The explanation must, doubtless, be sought in. the 

 difierent nature of the soil over which the rivers flow, and 

 the varied tinctorial qualities of the vegetation along the 

 courses of the streams. 



Two hours of steady rowing from Asaiba brought us 

 to Rio Claro, also a black-water river, where the banks 

 a^ain disappeared, and the stream lost itself in the Za- 

 guna de los Indies, a section of coimtry partially covered 

 with forest, in places so intricate as to make navigation 



