OF THE HAWAIIAN ISLANDS. 363 



and his rider without cracking. The salt covering the bottom is much fissured, and it is on 

 the edge of these cracks that the finest crystals occur. Large nodules, composed of bril- 

 liant cubes more than a third of an inch in diameter, are quite common in the water, and 

 usually contain no nucleus. The salt is quite pure, and large quantities have been taken 

 away for sale. 



On the shore towards the mountains (B) fresh water oozes in through the remains of aban- 

 doned kalo patches, but the cattle have so trodden the miry soil that it is difficult to trace 

 any stream. It is not possible that this lake has any communication with the ocean, as the 

 tides rise and fall nearly two feet on the adjacent shore, a change of level sufficient to alter- 

 nately drain and fill the shallow basin ; and a rise of an inch would cause an advance in 

 the shore line of at least a foot, while the most careful observations have failed to perceive 

 any change which could not be attributed to the varying winds. 



On the southern ridge near its base is a raised coral reef (A) much cracked and displaced, 

 and fragments of coral are imbedded in the tufa of the walls on every side. Towards Ewa 

 on the west is a hollow (D) which during the severe rains of the winter, contains a muddy 

 pool of brackish water ; this is separated from the salt lake by a narrow ridge, and is of 

 similar formation. 



At Laelda, the south-western point of Oahu, is a cluster of small cones, dis- 

 ° up ' tinctly visible from Honolulu, which bear marks of comparatively recent origin. 

 All these have craters, and in two of them the rock projects in rude columns. They are 

 mostly composed of a tolerably compact black lava, and are surrounded by lava of a red 

 color broken into large loose blocks from two to twenty cubic feet in size, precisely resem- 

 bling; the masses so common near Leuhi. The highest of these cones is but three hundred 

 feet above the sea, and, although from a distance conspicuous from its regular conical form, 

 is hardly larger than some of the lava bubbles on Hawaii. 



MAUI group. 



(See Map, Plate XIII.) 



The third division of the Hawaiian Islands consists of a group of islands of consider- 

 able extent. Maui, the largest, is next to Hawaii in size as well as in height, and contains 

 the largest known crater. Molokai, Lanai, Kahoolawe, and Molokini are small, seldom visited 

 by travellers, and have never been thoroughly explored. 



Although closely clustered, and forming, as it were, the fragments of a former island of 

 semicircular form, the members of this group exhibit some remarkable differences, both in 

 form and constitution. Maui contains a lava which has never been found on Kauai or Oahu, 

 while Molokai abounds in a light gray stone, which is not known to occur anywhere else. 

 M£ui and Molokai are islands of double summits like Oahu, while Lanai and Kahoolawe are 

 single, and resemble Niihau. The distribution of land-shells and of plants is also various, 

 each island having several peculiar species. Whether they ever composed one island, or 

 what their true relation to each other may be, will be examined further on ; at present it 

 remains to examine their physical and geological characteristics as separate islands. 



