220 Contributions to Physical Geography. 



square sea miles, and which cannot be estimated below 70,000 

 tons a-day, according to Halley. 



I have read in some manuscript historians of the Jesuits, 

 that in the interior of the lake Ybera, there lived an Indian 

 nation of pigmies, and a very detailed description of it is 

 given. But all this is false, and has no more reality than that 

 empire which is supposed to exist in the middle of the lake of 

 Jarages. The Ybera is a great extent of water, which in 

 some places forms a true lake ; but the larger portion of it is 

 filled with plants, so that it is impossible to explore the inte- 

 rior of it either on foot or on horseback, or in a boat. Its 

 situation, and the general disposition of the country, indicate, 

 that the river Parana formerly traversed this lake, and that it 

 afterwards divided itself into the four rivers which now flow 

 but of it. — Voyages dans VAmerique Meridionale, par Don 

 Felix de Azara, torn. i. p. 80 — 82. 



3. Account of the Cavern qfPla?iina 9 in Carniola. 



For about a quarter of a mile we followed the course of the 

 stream upwards through the narrow dell, bounded on both 

 sides by bold rocks, and tufted with luxuriant underwood. 

 A long array of corn and saw-mills succeeded. Above the 

 last of them, the dell is terminated by a semicircle of bold and 

 lofty precipices, in the middle of which an enormous archway, 

 almost as regularly formed as if hewn out by the hand of art, 

 opens a way into the entrails of the mountains. Through 

 this majestic portal, the river Laybach pours itself forth at 

 once from the bosom of the earth, and spreads out its waters 

 to the day in an ample basin, which extends on both sides to the 

 walls of rocks that bound the dell. The stem of a huge fir, 

 hollowed out like a canoe, furnishes the only means of reach- 

 ing the entrance, for the waters of the basin not only wash the 

 precipices, but, as was evident from the hollow sound of the 

 waves, have undermined them. A miller's man guided this 

 frail bark with a wooden shovel. The whole passage to the 

 opening does not exceed a hundred feet, and if one sits quiet- 

 ly, danger is out of the question. 



This natural gateway is about twenty feet wide, and twice 

 as high. It is regularly curved. A few steps forward, and 



