OF THE HAWAIIAN ISLANDS. 415 



that several changes of importance had taken place. The long ridge of blocks of compact 

 lava, like the upper wall which extends at intervals nearly around the northern edge of the 

 crater, had then formed. He says : " This ridge rose on its outer or eastern face often to 

 the height of fifty or one hundred feet, especially towards the south, where it approached 

 the great lake ; and generally it left a space or canal as it has been called, between it 

 and the ledge [black ledge of Prof. Dana] several rods in width, and in some places forty 

 or fifty feet in depth." The canal mentioned is the same one into which Mr. Coan saw the 

 lava flow in 1844. The lake at the southern end was still surrounded by a rim of lava, and 

 bounded on the north-east by a high plateau, — the raised floor of the crater. There was 

 no other lake or pool of lava visible. A curious dome, corresponding to the "hornitos," 

 described by Humboldt in the malpays of Jorullo, was observed about a mile north of the 

 great lake. It was ten or twelve feet high, its walls not " more than a foot thick, and 

 through two openings, the one a foot and the other half a foot in diameter, the interior was 

 revealed of a glowing white heat, and by throwing pieces of lava into these orifices they 

 were seen to fall into the pasty semifluid mass ten or fifteen feet below. This furnace was 

 in full blast six weeks after." ' 



Mr. Coan, in a letter dated December 7th, 1846, says: "Visited the volcano a few days 

 ago. Found the lake full and active. Dipped up the molten lava with our canes." So that 

 the lava must have risen ten or twenty feet in the few months since Mr. Lyman's visit, 

 when the lava was that depth below the rim. 



Mr. Coan again writes in a letter dated January 1851 : " My next visit to the crater 



D . . . 1847. 



was in July 1847, in company with Captain (late Admiral) Dupont and several officers 



of the United States ship Cyane. No essential changes had occurred in the bottom of the 

 volcano during this interim, except that the great lake had filled up, had overflowed a con- 

 siderable area around its rim, was still full and in an active state. The boiling of the lava 

 was intense around most of its circumference, and at many points over its surface. Access 

 to the red-rolling fusion was comparatively easy, so that by carefully watching and dodging 

 its fiery jets we could dip up its viscid matter with sticks or ladles. Silent and successive 

 overflowings took place from time to time during this year, considerably elevating all the 

 area in the vicinity of Halema'umau, but not affecting the other and larger portions of the 

 crater. I think it was about the beo-inninar of 1848, that the «;reat lake was first 



1848 



noticed as crusted over with a thick stratum of lava, and this stratum was soon 

 raised into a dome some two or three hundred feet high over the whole lake ; traversed 

 here and there by rents and fissures, and studded by an occasional cone. Occasionally the 

 visitor, or the passing traveller, would descry, through these fissures, the glowing of the 

 subterranean fires, and now and then the gory mass would be pressed sluggishly through 

 these chasms or driven up with more force through the several chimneys, apertures, or 

 orifices of the dome. These eruptions rolled in heavy and irregular streams down the sides 

 of the dome, spreading over its surface or cooling at its base. Thus the dome as it now 

 exists, has been formed by the compound action of upheaving forces from beneath, and of 

 eruptions from its openings forming successive layers upon its external surface. During 

 most of this year, however, an extraordinary inactivity prevailed throughout the crater. 

 During the summer and autumn when I was at Kilauea, there was no fire to be seen even in 



i SUliman's Journal of Science [n. s.], vol. xii., p. 75. From occupied the same position as at present. See the Plan of 

 a manuscript map prepared by Mr. Lyman, I find the " ridge " Kilauea, Plate XV. 



