44 C. H. HITCHCOCK — GEOLOGY OF OAHTJ 



before reaching port from the east, and again upon resuming their voyage. 

 Artists have vied with one another in efforts to display this beautiful hill 

 on paper or canvas, and every one is interested in viewing the channeled 

 water-courses upon the outside and the barren rocks as contrasted with 

 the rice fields, cocoanut groves, and the green plain of Waikiki, a health 

 resort, close to the city at its base. It is a truncated hollow cone, 4,400 

 feet in the greater diameter of the rim, and 4,300 in the shorter diameter. 

 The elongation is in the direction of the trade wind, and consequently 

 the southwest side is higher and thicker than its opposite. This fact, 

 first stated by W. L. Green and reiterated by all later authors, applies 

 to many others of the secondary craters as well and to the direction of 

 the spread of the eolian beds. The southern highest part is 761 feet 

 above the sea at its base, the opposite end being somewhat lower, and 

 there is not much variation in the rim elsewhere. Inside, in the wet 

 season, there is a pond at the lowest point, 200 feet above the sea, as near 

 as may be to the eastern wall. From the outside Diamond head looks 

 like a solid hill, and with its reddish tint and apparent strata is very sug- 

 gestive of buttes in the Chalcedony park of Arizona. 



The diameters of the base of this crater are 5,000 and 6,000 feet re- 

 spectively, making the seashore the extreme southwest limit. The tuff 

 has been recognized in the very deep well sunk by James Campbell near 

 the seashore at Waikiki. Two hundred and seventy feet of tuff were 

 penetrated by the drill beneath 50 feet of beach sand and gravel. The 

 diameter of the base may not be extensive enough, since the tuff crops 

 out at Kupikipikio nearly three-quarters of a mile easterly from the rim 

 of Diamond head. 



The structure of this cone is typical of its class — a broad, shallow, 

 saucer-shaped crater, with layers dipping toward the center inside, and 

 outside outwardly in every direction at angles of 30 to 35 degrees. It 

 would seem that the mud was forced directly upward from the center, 

 the surplus flowing over the outside of the cone in every direction, and 

 after the supply had ceased to come the inner portions fell back toward 

 the vent. The fragments consist of every variety of the older basalts, 

 with much limestone, corals, and shells that were torn off by the ascen- 

 sive force of the eruption from the coral reef beneath. Mr Green sug- 

 gested that some of the lime came from the evaporation of ocean water. 

 Nowhere is the lime more abundant than it is here among the secondary 

 craters. It has been dug out and used for chalk in the early days of the 

 settlement. The tuff has been much exposed to the elements, and is 

 consequently very friable. It is a palagonite like that of Punchbowl. 

 Professor Dana says that since 1840 the highest part of Diamond head 



