SPELEOLOGY, OR CAVE EXPLORATION. 257 



ground rivers of Istria, Carniola, and Herzegovina. Credits are 

 granted every year for enterprises which prove to be more useful 

 than would at first be thought. 



It was at the same time, between 1883 and 1885, that I made 

 my first investigation in the Causses of Lozere, Aveyron, and the 

 adjoining departments of France, the results of which were to re- 

 veal for the first time to the public, and even to geographers, the 

 picturesque beauties, then unknown, and now becoming the fashion, 

 of the gorges of the Tarn, Jenta, and Dourbie, the rocks of Mont- 

 pelier le Vieux, etc. In my excursions over the plateaus of the 

 Causses I frequently met, at the level of the surface, open, dark 

 holes, and mouths of vertical wells — averts — the depths of which no 

 one had ever looked into, unsoundable, they said, which the peasants 

 naturally took to be real mouths of hell. Recollecting what I 

 had admired at Adelsberg and in various caves of the Pyrenees, I 

 guessed these avens might also be doorways to subterranean splen- 

 dors and scientific treasures. So I began in 1888 the method- 

 ical exploration of the unexamined natural cavities of my own land 

 first, and then of other countries of Europe; and since then I have 

 devoted several weeks every year to this work. 



These pits are simply horizontal holes opening upon the surface 

 of the ground, of very different forms and dimensions. Herdsmen 

 are very careful not to let their cattle go too near them, for they 

 sometimes fall in. 



The diameter of these pits varies from a few inches to several 

 hundred yards, and they are sometimes more than six hundred feet 

 deep. It is not easy to go down into them, especially when they are 

 on high levels away from habitations and roads. In such cases a 

 considerable apparatus of ropes, rope ladders, telephone, portable 

 boat, tent, etc., has to be taken along. The first measurement with 

 the sounding line gives the depth only of the first pit — and there 

 are often several succeeding one another. A rope ladder long 

 enough to reach the bottom is then let down, and the man who 

 descends has a rope tied about him for additional security, which is 

 held by the people above. A great many pits are narrower at the 

 top than lower down, forming something like a reversed speaking 

 trumpet, so that the explorer finds it very difficult to make himself 

 heard at the top; hence I have adopted the practice of taking a 

 telephone along. The interior shapes of the pits are very diverse. 

 The narrower ones are easiest to go down, because they permit one 

 partly to support himself against their walls. The wider ones leave 

 him hanging loose, in a position which he feels to be very precarious. 

 When there is a second or third pit, and we have not ladders 

 enough, we have to trust ourselves to a simple rope with a board 



TOL. LIV. 19 



