CEEEOS BE SJSAPO. 
the tropics, as well as in the temperate zone. The violent 
winds of Neiva are not the effect of a repercussion of the 
trade-winds ; they rise where those winds cannot penetrate ; 
and if the mountains of the Upper Orinoco, the tops of which 
are generally crowned with trees, were more elevated, they 
would produce the same impetuous movements in the at- 
mosphere as we observe in the Cordilleras of Peru, of 
Abyssinia, and of Thibet. The intimate connection that 
exists between the direction of rivers, the height and dis- 
position of the adjacent mountains, the movements of the 
atmosphere, and the salubrity of the climate, are subjects 
well worthy of attention. The study of the surface and the 
inequalities of the soil would indeed be irksome and useless 
were it not connected with more general considerations. 
At the distance of six miles from the island of Piedra 
Eaton wo passed, first, on the east, the mouth of the Bio 
Sipapo, called Tipapu by the Indians; and then, on the 
west, the mouth of the Bio Yichada. Near the latter are 
some rocks covered by the water, that form a small cascade 
or raudalito. The Bio Sipapo, which Pather Grili went up 
in 1757, and which he says is twice as broad as the Tiber, 
comes from a considerable chain of mountains, which in its 
southern part bears the name of the river, and joins thfl 
group of Calitamini and of Cunavami. Next to the Peak 
of Duida, which rises above the mission of Esmeralda, the 
Cerros of Sipapo appeared to me the most lofty of the whole 
Cordillera of Parima. They form an immense wall of rocks, 
shooting up abruptly from the plain, its craggy ridge of 
running from S.S.E. to N.N.W. I believe these crags* 
these indentations, which equally occur in the sandstone ot 
Montserrat in Catalonia,* are owing to blocks of granite 
heaped together. The Cerros de Sipapo wear a different 
aspect every hour of the day. At sunrise the thick vege- 
tation with' which these mountains are clothed is tinged 
with that dark green inclining to brown, which is pecufia 1 ' 
to a region where trees with coriaceous leaves prevail' 
Broad and strong shadows are projected on the neigh' 
bouring plain, and form a contrast wdth the vivid ligW- 
* From them the name of Montserrat is derived, Monte S'errttw 
signifying a mountain ridged or jagged like a saw. 
