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the narrow, winding, and numerous channels of 

 the bocas chic as. As these little channels sepa- 

 rate at one point only from the principal trunk 

 near San Rafael, curious researches might be 

 made on the retardation of the tides, and the 

 propagation of the waves in the bed of the 

 Oroonoko, above and below San Rafael, at Cape 

 Barima in the ocean, and at the boca of Manamo 

 in the Golfe triste. Hydraulic architecture, 

 and the theory of the movement of fluids in con- 

 tracted channels, would alike gain from a labour, 

 for the execution of which the Oroonoko and 

 the Amazon furnish peculiar facilities. 



The navigation of the river, whether vessels 

 arrive by the Boca de Navios, or risk entering 

 the labyrinth of the Bocas chicas, requires various 

 precautions, according as the bed is full, or the 

 tvaters very low. The regularity of these pe- 

 riodical risings of the Oroonoko has been long 

 an object of admiration to travellers, as the over- 

 flowings of the Nile furnished the philosophers 

 of antiquity with a problem difficult to solve. 

 The Oroonoko and the Nile, contrary to the 

 direction of the Ganges, the Indus, the Rio de 

 la Plata, and the Euphrates, flow alike from 

 the south toward the north ; but the sources 

 of the Oroonoko are five or six degrees nearer 

 the equator, than those of the Nile. Obser- 

 ving every day the accidental variations of 

 the atmosphere, we find it difficult to persuade 



