J. 8. Emerson—Kilauea after the Eruption of 1886. 89 
this reason I prudently refrained from trusting myself to their 
support, and did not approach near enough to the sides to ex- 
amine the material of which they were composed. It presented a 
recular, lusterless surface, quite free from projecting rocks and 
also without notable fissures, and bore a strong resemblance to 
coarse gravel or small fragments of broken lava rock. Ata 
depth, which I estimated at about 275 feet below the upper 
edge of this pit, was the very bottom of Halema’uma’u, an 
apparently smooth surface of black pahoehoe, entirely free 
from fallen rocks or debris, approximately in the shape of an 
equilateral triangle of about twenty-five feet on a side. It was 
not as level as the surface of a newly cooled lake. A portion 
rose somewhat irregularly above the rest and gave the impres- 
sion of a mass of solid rock covered over with a thin coating 
of fresh pahoehoe. Near the northeasterly vertex was a small 
fissure from which arose a slender column of faint bluish 
smoke. The base of this smoke column afterwards served me 
as a convenient substitute for a flag in my triangulation, by 
which I accurately determined the depth of Halema’uma’u to 
be 900 feet below the datum at the Volcano house. I daily 
watched the smoke jet above described in hopes of seeing 
some marked change, but I was always disappointed. 
The point of greatest interest to me was within the sunken 
area of Halema’uma’u, 750 feet northwest of the smoke jet in 
the central pit and 364 feet above its level. My attention was 
first particularly directed to it April 5th. While engaged in 
the survey of New Lake I noticed at that time a continuous jet 
of steam arising from this point. It had burst through the — 
broken lava rock and had already made for itself an oval- 
shaped aperture, perhaps five or ten feet across. I thought I 
had seen it from the Volcano house for a day or two before, 
but had not made any special note of it. I now began to 
watch it carefully. The next morning, on observing it with a 
glass from the Volcano house, there was a marked change in 
its appearance, and I soon saw that it was no longer a jet of 
pure white steam, but of pale bluish, sulphurous smoke. The 
continued rainy weather prevented my visiting it again until 
April 8th, when I observed that the size of the aperture, as 
well as the volume of smoke had greatly increased. After 
another vexatious delay of several days owing to rainy 
weather,—wind from the northeast, regular trades,—I made 
my final visit to it on the 12th of April, when through the 
rift in the smoke, which was now pouring out from this elon- 
gated aperture, I saw the newly formed bank of glistening 
sulphur on the southwest side. As Iwas surveying in that 
vicinity I had occasion to occupy the station which I had 
already fixed at Halema’uma’u W., on the edge of the precipice 
