i < rnando <U JVbronha. 





this respect, and not only animal remains but stonefi the size of 

 a man's fist may be found where, under ordinary circumstances, 

 ir would be quite impossible for the wind to blow them. 



On the south Mdo of Ilha Rapta where the Beolian smdstone 

 conies in contact with the underlying eruptive rocks, at a place 

 known as the Funil or "Mow hole" already referred to, a 

 maze of subterranean channels has been cut out by natural 

 pro The upper part of the sandstone is worn away 



leaving a thin but compact horizontal crust forming the roof 



of these caverns (see fig. 8). Through this roof are three or 

 four openings, and at certain stages of the tide the waves beat- 

 ing against the shore, at this point Y-shaped in outline, crush 

 and compress into these subterranean channels great bodies 

 of air which, when they happen to be carried to the openings 

 through the roof, escape with enormous violence. I have seen 

 the spray from one of these holes (the one seen on the left in 

 the sketch), thrown to a height of more than a hundred feet. 

 Sometimes but little water is ejected, the air escaping with a 

 Joud explosion and resembling hot air rushing: under pressure 

 from a furnace. These explosions come principally from the 

 vent shown on the right in the illustration. At other times a 

 great body of water spurts from the largest of the openings — 

 the one in the middle of the foreground. One of the prisoners 

 living on Ilha Rapta told me that he had known fishes and 

 stones to be thrown out by these jets of water and to fall on 

 the sandstone above. There are a few loose stones lying over 

 the surface of the calcareous rock within the range of the fall- 

 ing spray, and it is not improbable that fragments of corals, 

 impossible of transportation by the wind, might be in this way 

 thrown upon the higher parts of the calcareous sandstone 



