36 A NATURALIST IN THE PACIFIC cha 



a half-forgotten thermal spring in a swamp. From this cause alon 

 I no doubt failed to find several springs. All the boiling spring 

 and those of very high temperature are probably known ; but as i 

 pointed out below it is more than likely that a large number c 

 unimportant springs remain to be discovered in many a deserte 

 inland valley and between the tide-marks along the very extensiv 

 reef-bound coasts. 



As above remarked the hot springs did not come under m 

 notice in all parts of the island. They are to all appearance wani 

 ing in the western or Mbua portion, and also in the Undu portio 

 north of Natewa Bay. Taking the first-named region, it will b 

 noticed that no hot springs are indicated in the map west of th 

 Ndreketi and Wainunu rivers. I made inquiries wherever I wen 

 but with no result. On my writing to Mr. Wittstock, of Mbai 

 lailai, who is well acquainted with the Mbua peninsula, he informe 

 me that if hot springs existed in that part of the island he woul 

 probably have known of them. In that portion of the island whic 

 ends in Undu Point I could neither discover nor hear of an 

 thermal springs east of Lambasa on the north side, and of Lakemb 

 on the south or Natewa Bay side ; nor could Mr. Bulling, who ha 

 resided at Undu Point for many years, tell me of any springs i 

 his neighbourhood. 



On looking at the general map it will be observed that th 

 hot springs are confined to the area of basic rocks, although the 

 do not occur all over that area, not being indicated in the map t 

 the west of the Ndreketi and Wainunu rivers. They are not know 

 to occur in the region of dacites and acid andesites, as in the cas 

 of the Drandramea district ; and they have not been found in th 

 area of rhyolitic and trachytic rocks that extends from Undu Poir 

 to Mbuthai-sau on the north coast and to near Tawaki on th 

 Natewa Bay side. The region of hot springs would be limited o 

 the east by a line joining the Mbati-ni-kama springs with those ( 

 Nandongo on the Wainikoro river and Natuvo on the north shoi 

 of Natewa Bay. Such a line, though lying within it, roughl 

 indicates the limit between the regions of basic and acid rocks. 



The situation of the hot springs in the lower levels, and the 

 non-discovery at elevations exceeding 300 feet above the sea, ai 

 facts of importance. In more than half the cases they arise clos 

 to and often on the banks of streams and rivers, occasionally indee 

 at the river-bottom ; and no doubt numerous unknown thermi 

 springs issue under water from the river beds. In about a thir 

 of the known cases the springs come up on the coast between th 



