220 



all probability have been left on the raft, fubtended in the air by the branch ; in which 

 cafe, the lighted misfortune I fhould have incurred, would have been the lofs of my 

 journals and obfervations, the fruit of eight years* toil. I fucceeded, fortunately, in dif- 

 engaging the raft, and fetting it again on float. 



I availed myfelf of my obligatory flay at Sant Yago to meafure trigonometrically 

 the breadth of the two rivers, and to take the angles required to enable me to draw a 

 topographical chart of the Pongo. 



The 1 2th July, at noon, 1 caufed the raft to be unmoored, and puflied from fhore ; 

 foon I found myfelf carried along by the ftream in a deep and narrow gallery, formed 

 by two walls of rock, in fome parts flanting, but in others perpendicular ; in lefs than 

 an hour, I was tranfported to Borja, three leagues, according to common computa- 

 tion, from Sant Yago. However, the Balfe, which did not draw half a foot of water, 

 and which, from the bulk of its loading, prefented to the air a refiftance feven or eight 

 times as great as that it oppofed to the current, did not confequeritly proceed with equal 

 velocity to that of the current itfelf ; and this velocity diminifhes m.aterially as the chan- 

 nel increafes towards Borja. In the narrowell part I reckoned, that, comparing the 

 fpeed of our courfe with that on former occafions, which 1 had meafured trigono- 

 metrically, in the narrowefl part, we were carried along at the rate of two toifes in a 

 fecond. 



The channel of Pongo, hollowed by the hand of nature, begins a fliort league be- 

 low Sant Yago, narrowing gradually till, from 250 toifes, the breadth at the junction 

 of the two rivers, it diminifhes in the narrowefl part to twenty-five. I know very well, 

 that the breadth hitherto afcribed to the narrowefl part of the Pongo, is only five and 

 twenty Varas, equivalent fcarcely to ten of our toifes ; and that the paffage from Sant 

 Yago is faid to be effected in a quarter of an hour. For my part, I remarked that, in 

 the very narrowefl part, I was at leafl thrice the length of my raft from either fide. 

 I moreover obferved by my watch, that we were fifty-feven minutes in fpeeding from the 

 entrance of the flrait to Borja, and all Combined, I found the meafures as I have given 

 them ; and, however well inclined to fliew a deference to the opinion commonly re- 

 ceived, I can fcarcely admit the diflance from Sant Yago to Borja, inflead of three, as 

 computed, to be even fo much as two leagues, of twenty to a degree. 



I flruck twice or thrice with violence againfl the rocks in courfe of the different 

 windings, an accident calculated, but for being forewarned of the little danger thence 

 to be apprehended, to create no fmall portion of alarm. A canoe on fuch an occa- 

 fion would be dafhed into a thoufand pieces ; and the fpot was pointed out to me, as 

 I paffed along, where a governor of Maynas thus met deftrudion : but the beams of 

 the raft being neither nailed nor dovetailed together, the flexibility of the Lianas, by 

 which they are faflened, have the effeO; of a fpring, and deadens the fhock fo, that 

 when the flrait is paffed in a raft, thefe percuflions occur unheeded. The greatefl 

 danger for thefe is, their being liable to be driven out of the flream into eddies, an 

 accident which, as related above, it was my lot to experience. Not a year had elapfed 

 before fmce a mifllonary, drawn thus into a vortex, was kept in it for two days defli- 

 tute of provifions ; and, but for a fudden fwell of the river, which brought him again 

 into the current, he might there have perifhed of hunger. The Pongo is never at- 

 tempted in a canoe, except when the waters are fo low as to admit its being fleered 

 without being overpowered by the flream. Canoes alfo flem the current when the 

 waters are at their lowefl, and afcend ; but this is imprafticable for Balfes. 



At Borja, I found myfelf in a new world, feparate from all human intercourfe, on 

 a frefh water fea, furrounded by a maze of lakes, rivers, and canals, penetrating in 



every 



