OEOLOOICAL CONCLUSIONS. 3fil 



In the raised coral rock of Oahu (p. 339) there are several 

 long winding horizontal chambers, some of which are the 

 sources of subterranean streams that open out on the shores 

 between the layers of the rock, or from the mouths of caverns. 

 These running waters, and others trickling from above, are 

 obviously the eroding agents that have made the caves. 



As briefly remarked on page 194, caverns are still more re- 

 markable on the island of Atiu, on which the coral reef-rock 

 stands at about the same height above the sea as on Oahu, 

 Rev. John Williams states that there are seven or eight of 

 large extent on the island. Into one he entered by a descent 

 of twenty feet, and wandered a mile in one only of its branches 

 without finding an end " to its interminable windings." He says, 

 " Innumerable openings presented themselves on all sides as 

 we passed along, many of which appeared to be equal in height, 

 beauty and extent to the one we were following. The roof, a 

 stratum of coral rock fifteen feet thick, was supported by massy 

 and superb stalactitic columns, besides being thickly hung with 

 stalactites from an inch to manv feet in length ; some of these 

 pendents were just ready to unite themselves to the floor, or to 

 a stalagmitic column rising from it. Many chambers were 

 passed through whose fretwork ceilings and columns of stalac- 

 tites sparkled brilliantly, amid the darkness, with the reflected 

 light of our torches. The effect was produced not so much by 

 single objects, or groups of them, as by the amplitude, the 

 depth, and the complications of this subterranean world." 



Other similar caves exist on the neighboring island of 

 Mauke. 



The Bermudas are also noted for their caverns. The coral- 

 made land here stands in some places 260 feet above the sea. 

 Lieutenant Nelson speaks of the caverns as large and beauti 

 ful — one of them " a perfect bijou." 



