SUBSIDENCE OF THE DEBRIS CONE.
It is worthy of note that in the next series of changes the area of the more elevated part of this cone becomes the depressed area of August, 1892, as shown by the section and map of that date; and a description of the changes follows.
S. E. Bishop. In the collapse of March 7, 1891, the debris cone, Dana and Maby lakes disappeared, leaving a pit seven hundred feet deep. Lava soon returned, and for one year has been gradually rising. In Dana Lake the lava had issued quietly from the center towards the walls and descended car rying sections of the crust. Now the edges are quiet. The current starts from east of the center and flows westward. Pieces disappear in the vivid melee of the center. The cone form of Halemaumau becomes more distinct. (Written April I I, 1892.) There was a slight earthquake when the change took place, and it was exactly five years between the last two collapses. As the debris cone was about two hundred feet high its apex was only eighty-eight feet below the Volcano House—the highest point attained by the rock during the whole history of the volcano, or 3,955 feet above the sea. The melted lava probably reached the height of three hundred and seventy feet below the Volcano House.
March 18, 1891. A sheer precipice around Halemaumau. Depth a little less than in 1886. E. P. Baker.
May 19. W. R. Castle says that Halemaumau is a profound abyss i,800 feet in diameter and nearly three hundred feet deep. Mr. E. N. Hitchcock succeeded in making the perilous descent to the bottom over large blocks of lava. On the northeast side of the lake is a cone ejecting lava.
Sept. 14. E. P. Baker. In May the lava lake was four hun dred to five hundred feet below the edge. Now it is about two hundred. Lava flows from N. W. to S. E.
Nov. 30. H. M. Whitney says the lake is i,000 to 2,000 feet across, throwing up several large jets and thousands of small ones. There are two openings near the center allowing the lava to ascend and descend.
Feb. 12, 1892. L. A. Thurston. Diameter of the pit 2,500 feet. It is two hundred and fifty feet down to the black ledge, which is twenty-five feet high and two hundred feet broad. It is 1,30o feet from bank to bank of the lake next to the black ledge. J. M. Lee says that two months ago the molten lava
sank one hundred and fifty feet below the level of the black ledge. After one month it began to rise again and lacks now only twenty-five feet of its pristine level. Lava boiling with bursts of spray twenty-five feet to fifty feet. No upward thrust. The filling is by overflow from the central lake.
The condition of things in Kilauea after the changes of March 7th, 1891, have been very intelligently described by Professor A. B. Lyons." He spoke first of the appearance in 1889, and found in 1892, July II, everything so changed that nothing in the vicinity of Halemaumau was recognizable. The debris-cone with the attendant clouds of steam and smoke had vanished. From the hotel, one would say that the volcano has entirely disappeared ; and nothing suggestive of great impor tance was perceptible till the pit itself was close at hand, which was enclosed by a precipice constituting a circular rampart two hundred and fifty feet deep, half a mile in diame ter. The sides consisted of irregularly bedded lava varying in hue from gray to brick red ; the floor of fresh black pahoe hoe with a fluid center or lake partly quiet and partly boiling like a witch's caldron. The lava pool occupies about fifteen acres with banks from five to ten feet high.
The lava blocks are loosely piled beneath the precipice over which by care it is possible to make one's way. The lake is twenty-five to thirty feet higher than the base of the walls of the pit. On the south side the lake is held in place by a sort of levee of slight thickness over which the lava pours in a magnificent cataract not less than fifteen feet in perpendicu lar height.
So much lava rises from below that the level of the lake is constantly rising and changing its area. One evening there were overflows from three different points at once, and within two hours' time fifteen acres of the black lava were inundated. The heat is intense, and one is in danger of being bombarded by the spurts of the fiery liquid. It was dangerous to go to leeward of the lake because of the unexpected flows of lava which might cut off one's retreat or raise the temperature of an inclosed space to an unendurable degree.