CHAP. XXV.] BOILING PONDS. 383 



visions resulting from the gradual deposition of the 

 silex. The water which falls over them was mode- 

 rately tepid. The steps are firm like porcelain, and 

 have a tinge of carmine. The concretions assume 

 interesting forms of mamillary stalagmites of the 

 colour of milk-white chalcedony; and here and 

 there, where the rounded steps overhung the former 

 deposits, stalactites of various sizes were depending. 

 The boiling pond on the top, which was clear and 

 blue, could not be approached, as the concretions at 

 its margin were very thin and fragile. The pond 

 was about ten yards round, and perhaps one hundred 

 feet above the level of the Rotu-Mahana. The water 

 which is discharged into the lake from this pond 

 and from other places warms its waters to 35 Fahr. 

 above the temperature of the air, that is, to 95. 

 There are also springs in the lake itself, as in many 

 places bubbles are seen rising up. On the banks of 

 the lake are a great many openings from which 

 steam issues. We afterwards landed on a small 

 rock in the lake, composed of a felspathic lava ; the 

 natives had some houses on it, and cooked our food 

 over a steaming crevice, while I bathed in the warm 

 lake. 



The Rotu-Mahana is not more than a mile in cir- 

 cumference. We crossed from it in a canoe into the 

 lake of Tera-wera. The stream connecting them is 

 tepid and of a temperature of 85. It is more ap- 

 propriately called Kai-waka (canoe-spoiler), as the 

 canoe often touches the rocks of which the bottom 



