24 A NATURALIST IN THE PACIFIC chap. 



C. Pool 12 feet wide, ioo yards from village, near the river . 103 F. 



D. Pool on the road to Mbale-mbale, mixed with surface water ioo° „ 



The natives and others often state that the thermal springs here 

 and in other localities are much hotter in dry than in rainy weather. 

 This is correct in a sense, because in wet weather the surface water 

 would usually find access to the pools ; but there is no reason to 

 believe that the temperature of the water at the hole of exit varies 

 at all from this cause. The temperature of pool A was taken at the 

 bottom where the water bubbled up ; and probably it represents 

 the true degree of heat of these springs, since in the other cases 

 observation of this point was not so easy. The weather was dry 

 during this visit ; but, three months before, I tested the temperature 

 of this pool after heavy rain, when the district was flooded, and then 

 I got a reading of 127 at the exit-hole of the spring. 



Another thermal spring, which is distant about a mile from 

 Natoarau, is known as Waitunutunu, that is, Warm Water. It lies 

 about a third of a mile from the village of Nambuniseseri, between 

 Mbale-mbale and Waisali, and is quite four miles inland and 

 about 100 feet above the sea. The springs bubble up into a pool, 

 about 12 feet across, which is close to a brook and had a tempera- 

 ture in March, 1899, of 109 — 112° F. 



3. The Hot Springs of Nukumbolo. — The village of Nukum- 

 bolo, where the springs are situated, lies on the banks of a tributary 

 of the Vatu-kawa branch of the river Ndreke-ni-wai, and is distant 

 as the crow flies about six miles inland from the river's mouth. 

 The springs issue on a hill-slope from several places a few steps 

 apart, and are removed about a hundred yards from the river, and 

 from 20 to 30 feet above it. Their elevation above the sea would 

 be about 1 30 feet. The temperature taken in the two hottest places 

 was 157° F, in November 1898, and 158 in the following February. 

 As in the case of the springs of Savu-savu and a few other localities, 

 the rocks are coated with siliceous sinter mixed with carbonate of 

 lime, and a gelatinous incrusting alga grows on the borders of tiny 

 hollows bathed often in water of a temperature 137-140 , but 

 thriving most where the temperature is 115-120 . The water runs 

 down the slope into a series of pools made by the natives for 

 bathing, the temperature of the lowest pool being 103-105 and of the 

 highest 1 20 . This is one of the best localities I have seen in the island 

 for the erection of thermal baths. The rock pierced by the springs 

 is apparently a basic agglomerate-tuff. Large blocks of a hard and 

 somewhat altered palagonitic tuff lie around the bathing pools. 



