I 



THE COMPLETED ATOLL. 249 



composed of fine sand and small fragments of corals and shells 

 mixed with considerable guano ; on the eastern or windward 

 side it is much wider, and formed of coarser fragments of corals 

 and shells, which, in their arrangement, present the appearance 

 of successive beach formations. Encircled by this ridge lies 

 the guano deposit, occupying the central and greater part of 

 the island. The surface of this deposit is nearly even, but the 

 hard coral bottom which forms its bed has a gradual slope 

 from the borders toward the centre, or, perhaps more properly, 

 from north-west to south-east, giving the guano a variable depth 

 from six inches at the edges to several feet at the deepest 

 part. 



Howland's Island is situated in lat. 0° 51' north, and 176° 

 32' west from Greenwich. It is about a mile and a half long 

 by half a mile wide, containing above the crown of the beaCh 

 an area of some 400 acres. The highest point is seventeen 

 feet above the reef, and ten or twelve feet above the level of 

 high tide. The general features of the island resemble those of 

 Baker's. Its surface, at least on the western side, is somewhat 

 depressed, and much of it is covered by a growth of purslane, 

 grass, and other vegetation, like that on Baker's Island, but 

 considerably more abundant. Near the centre of the island 

 there are one or two thickets of leafless trees or brushwood, 

 standing eight or ten feet high, and occupying an area of 

 sev^eral acres. The tops of these trees, in which the birds 

 roost, are apparently quite dead, but the lower parts, near the 

 roots, show signs of life after every rain. The windward side 

 of the island is formed by a succession of ridges composed of 

 coral debris with some sand and shells, running parallel to the 

 eastern beach, each one of which may, at earlier stages of the 

 island's growth, have successively formed the weather shore. 

 Occasionally among these ridges a sandy bed is met with, in 

 which some little guano is mixed. On the lee side there is 

 also a sandy margin of considerable width. Bits of pumice 

 and pieces of driftwood are scattered all over the island's 

 surface. 



The main deposit of guano occupies the middle part of the 



