BY THE REV. J. E. TENISON-WOODS, F.G.S., &C. 713 



jets from top to bottom. Wherever they occurred a little efflor- 

 escence of yellow colour could be also seen. 



The ti-ack which leads down to the crater, or rather the tracks, 

 for there are two, were well beaten, as if they had been well used 

 by many travellers and by the Indians. They were made of 

 zig-zag shape, so that there was not the slightest difficulty nor 

 danger in either ascending or descending. I noticed in many places 

 by the side of the track, small sulphur fumes, and, as I have 

 already mentioned, an iron point thrust into the ground showed 

 that at no great depth it was red hot. Since the last eruption 

 no doubt all these conditions have changed, but I was told by one 

 of the Indians that the slope of the sides was still the same. In 

 any case, supposing that there was no change, I should strongly 

 advise any tourist never to descend alone into the crater, even with 

 guides, for the dangers, though not very apparent, are really very 

 great. The heat and vapours are, at best, almost overpowering, 

 and a very slight change of the conditions might intensify both to 

 an extent incompatible with the existence of human life. Such 

 changes must be constantly occurring even in the most tranquil 

 periods of the volcano's history. 



Barometrical measurements prove that the level of the waters 

 in the crater is about the same as the level of the lake. It would 

 be difficult to suppose any connection between the two. Senor 

 Centeno suggests that the waters are entirely due to the internal 

 drainage during the long and heavy rainy season in this locality, 

 and that the heat causes them to have a strong chemical action, 

 dissolving the felspars, sulphates, and chlorides, with which they 

 come into contact. The heat of course is supplied by the volcano. 

 Something of this kind must be the true explanation, but one is at 

 a loss to know why similar phenomena are not seen in other lake 

 craters. The crater of Bromo, in Java, is perfectly enclosed, but 

 there is no accumulation of water at the bottom, and other 

 instances might be cited. Usually extinct craters are full of 

 water, and this is the origin of some of the most beautiful lakes 

 with which the surface of the earth is adorned. " As crater-rings 

 are usually composed of materials more or less impervious to 



