The further history of this spot is given by the statements of Professor L. L. Van Slyke who saw what was transpiring July i9th. The conical pit was not nearly filled up but there was a mound of lava blocks one hundred and fifty feet high taking its place, with a depression encircling it. A lava lake of about five acres in extent appeared in this depression and there were other active fires. He says: "Ascending the cone part way, I came to the edge of a deep hole or well, of rather irregular outline, four sided, perhaps thirty or forty feet wide, and from sixty to seventy five feet long, and not less than a hundred feet deep. The mouth was surrounded by masses of loose rocks, rendering approach to the edge impossible or very dangerous, except at one point ; from this point I could see the bottom of the well, and that it was cov ered with hardened fresh pahoehoe. At one side the liquid lava could be seen as it was puffed out of a small hole every few sec onds and thrown up a few feet. The puffing noise accompanying the ejection of the lava was quite like that of a railway locomotive, though louder. The aperture through which the lava was thrown out might have been three feet long and two feet wide. Immedi ately beneath the point where I was standing there seemed to be a constant and tremendous commotion, attended by a peculiar swashing noise, but I could not lean sufficiently far over with safety to see anything. Fumes of sulphur dioxide were coming up in abundance, but being on the windward side I was not great ly annoyed by them." From the southeastern side he ascended the cone and came to "a second well or deep hole, where molten lava was visible. This well was nearly round, with a diameter of perhaps twenty or thirty feet, and a depth of about a hundred. * * * Like the other well, the sides were perpendicular. At the bottom was a cone having an opening at the top perhaps ten feet across ; and inside liquid lava was boiling with intense violence, every few seconds throwing up a jet of lava, the spray of which came to the mouth of the well almost into my face." In addition to these holes, Professor Van Slvke visited a lake of lava located beneath the west wall of Halemaumau in the de pression, and extending about four hundred feet to the "smoke jet." At first the surface was hardened and black ; later there were spasmodic discharges of lava.
In September Mr. F. S. Dodge spent a fortnight at Kilauea ob serving the growth of the cone in Halemaumau and perfecting the data for a map supplementary to that of J. S. Emerson. A drawing made October i8th, Plate 37B, shows several steam holes upon the surface of the cone, a to g. Mr. Dodge noted the rise of the general floor due to the flow of the lava from Halemaumau. He also measured the debris-cone whose beginning had been de scribed by Van Slyke. It was i,o8o feet broad from N. E. to S. W., 1,10o from E. to W. and nine hundred and thirty from N. W. to S. E. Hence as the width of the general basin was 2,300 feet there was a depression encircling the cone with a width of from five hundred to seven hundred feet. The highest point on the cone was not quite as high as the surrounding black ledge. A section showing the relations of the cone and the black ledge appears in Plate 38, No. 3.
The most important discovery made by Mr. Dodge was the fact that the whole basin with the cone was rising at the rate of nearly one foot daily. By January 14th, 1887, it had risen two hundred feet since October, i886, as though floating upon the surface of a liquid lake. One of our illustrations shows this cone as it ap
peared in October.
Nov. 4, i886. W. R. Castle noticed that heat was perceptible in the fissure of i868 near Kilauea iki. He also visited Kama kaopule, a crater southeast from Kilauea iki. It is a pit five hundred feet deep, one-half of which is filled with sand. Steam was issuing from a crevice in the road quite near it. And it is said there is a very hot mound, now perceptible, (19o8), west of the road, towards Kau.
In August, 1887, Kilauea was visited by Professor J. D. Dana, who has fully described the history of Halemaumau since the eruption in March, He found the top of the cone to be high above the rim of the Halemaumau basin ; and that it was literally a debris-cone made of fragments of the lava crust and not of loose scoria such as comes from the central vent. "In the basin about the cone, the chief boiling lava lake was on the west side, in full view from the top of the west wall. The lake was about one hundred and fifty by one hundred and seventy-five feet in its diameters. Although mostly crusted over, it showed the red fires in a few long crossing lines (fissures), and in three to five open places, half-way under the overhanging rock of the margin where the lavas are dashing up in spray and splashing noisily, with seem ingly the liquidity of water. Now and then the fire places widened out toward the interior of the lake, breaking up the crust and consuming it by fusion ; yet at no time was there a projection of the lavas in vertical jets in a par-boiling way ; nor was it too hot to stand on the border of the lake if only the face were pro tected. Although relatively so quiet, the mobility of the brilliant splashing lavas made it an intensely interesting sight. Occa sionally the red fissures widened by a fusing of the sides as the crust near by heaved, and the lavas flowed over the surface. It was evident from the cooled streams outside, that now and then more forcible movements take place, followed by outflows over the margin ; when the whole lake is in action. There were no true well-defined jets rising and falling over any part of the sur face, like those of 184o, a condition requiring a little more heat; but the splashing at the margin, also due to the escape of vapor bubbles, had all the freedom of movement of splashing waves on a seacoast. The existence of the half-covered caverns along the margin, which the descriptions show to have been the most com mon feature for a score of years, was owing to the protection from cooling given by the overlying rock. All parts of the basin had been overflowed from fissures or temporary lava pools." This pool has since been named Dana Lake.
Our friend took great interest in the formation of the wrinkles on the surface of the cooled lava streams which give the look of tapestry folds, and are similar to the ropy lava of many authors. The stream of lava moves beneath the thin crust while it is cool ing; and the little waves thus produced are too stiff to fall back to their original horizontality. The wrinkles must be at right angles to the direction of the movement. Good photographs of recently cooled lava show both these concentric tapestry lines and also many oven-shaped domes sometimes fifteen or twenty feet high. Commonly their surfaces are broken because of the run ning away of the molten lava inside and the inability of the roof to sustain weight. One often develops this fracture in walking over an old lava stream.