CATAKACTS OF THE ORINOCO. 163 



jects to the far west towards the mountain of Uniama. From 

 this ridge descend four streams, which mark, as it were, the 

 limits of the cataracts of Maypures ; two bound Sipapo and 

 Sanariapo, on the eastern shore of the Orinoco ; and two the 

 Canieji and Toparo, on the western side. At the site of the 

 missionary village of Maypures the mountains form a wide bay 

 opening towards the south-west. 



Here the stream rushes foaming down the eastern declivity 

 of the mountain, while far to the west traces remain of the 

 ancient and now forsaken bank of the river. An extensive 

 Savannah stretches between the two chains of hills, at an 

 elevation of scarcely 30 feet above the upper water-level of the 

 river, and here the Jesuits have erected a small church formed 

 of the trunks of palms. 



The geognostical aspect of this region, the insular form of 

 the rocks of Keri and Oco, the cavities worn in the former by 

 the current, and which are situated at exactly the same level 

 as those in the opposite island of Uivitari ; all these indica- 

 tions tend to prove that the Orinoco once filled the whole of 

 this now dried-up bay. It is probable that the waters formed 

 a wide lake, as long as the northern dam withstood their 

 passage. When this barrier gave way, the Savannah now 

 inhabited by the Guareke Indians emerged as an island. The 

 river may perhaps long after this have continued to surround 

 the rocks of Keri and Oco, which now picturesquely project, 

 like castellated fortresses, from its ancient bed. After the 

 gradual diminution of the waters, the river withdrew wholly 

 to the eastern side of the mountain chain. 



This conjecture is confirmed by various circumstances. 

 Thus, for instance, the Orinoco, like the Nile at Philas and 

 Syene, has the singular property of colouring black the red- 

 dish-white masses of granite, over which it has flowed for 

 thousands of years. As far as the waters reach one observes on 

 the rocky shore a leaden-coloured manganeseous and perhaps 

 carbonaceous coating which has penetrated scarcely one- 



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