640 THE FRESH-WATER LOCHS OF SCOTLAND 
mouth of the Mamore to the Pilconiayo (that is, right across the 
main Amazon-Parana divide), "are inundated from October to March, 
and present the aspect of a great ocean studded with green islands. 
. . . Across the Monde Grande, a simply overturned tree would change 
the course of the waters."" ^ 
Lake of Maracaibo is a marine inlet, the largest in South 
America, 137 miles long by 75 miles broad, 9000 square miles in area, 
but it is rather of the nature of a lake or lagoon than of a gulf, being 
so entirely landlocked that the tides are scarcely felt a little way 
inside the bar. Beyond the bar the waters are quite fresh, the 
supplies received from the surrounding streams being greatly in excess 
of the marine currents. The greatest depth is 500 feet, but the 
stream deposits are slowly filling up the inlet. 
Lake of Valencia, in Venezuela, 22 miles broad and 300 feet 
in maximum depth, which fills a great part of the rich Aragua 
valley, is one of the most remarkable sheets of water in the world, 
for, although it seems completely encircled by the coast and inland 
ranges, it has two different outlets, on the western shore close to 
the city of Valencia, by one of which it has occasionally sent its 
overflow through the Trincheras northwards to the Agua Caliente, an 
affluent of the Caribbean Sea, and by the other it has communicated 
several times through the Paito southwards with the Pao, a tributary 
of the Orinoco. According to the oscillations of level the southern 
emissary has thus been alternately an affluent and an effluent. The 
water had been steadily subsiding for some years before 1882, but 
since that time the lake appears to be rising to its former high level 
when it discharged into the Orinoco ; the waters of the lake have 
become slightly brackish. 
The lakes situated along the Great Andes in Chili and Patagonia 
are numerous. In Chili, south of Arauco, there are many lakes, all 
regarded as being very deep, although few trustworthy soundings 
have yet been carried out. 
Lake Nahuelhuapi, in Patagonia, 2000 feet above sea-level, the 
source of one of the head-streams of the Rio Negro, is about 40 miles 
Ions:, with an extreme breadth of 9 or 10 miles. 
Lake Buenos Ayres, in Patagonia, about 50 miles long by about 
12 miles broad, presents a very remarkable hydrographic feature. ^ 
The lake draws most of its waters from the northern glaciers by 
means of a fairly large river called the Fenix. For about 30 miles 
1 Castlenau, quoted by G. E. Church, "Argentine Geography and the Ancient 
Pampean Sea," Geogr. Journ., vol. xii. p. 389, 1898. 
2 See J. W. Evans, "Hydrography of the Andes," Geogr. Journ., vol. xxv. 
p. 71, 1905. 
