Changes in Haloiiaiouaii. 



189 



angle. At the level of the lake, and half filled by it, was a great cavern extending in a south- 

 easterlj' direction from the lake [see Fig. 116]. The dimensions were apparently- seventy-five feet 

 across and fifteen feet from the surface of the lake to the roof of the cave. It could be seen into from 

 the opposite bank for about fifty feet. This may have been the duct through which the lava had 

 been drained, although it manifestly was not at the bottom of the lake, for up to July i6th, that had 

 continued to rise and fall from five to ten feet a day, and constantly threw up fountains, somewhat 

 more actively than before its subsidence. The entire area of subsidence is estimated to be a little 

 less than eight acres, about one-half of which fell into the lake. While the breakdown was taking 

 place there were many slight tremors of the binks generally resulting in the precipitate retreat of 

 the observers from the edge, but although the danger was great the spectacle was so grand and fas- 

 cinating that the party returned again and again to watch it. At the Volcano House two slight 

 earthquakes were felt on the afternoon of the nth, and one vigorous one at 2 a.m. on the 12th. 

 During the week several slight shocks were felt in the town of Hilo, thirty miles away, yet none were 

 felt at Olaa, half way between, nor at Kapapala, fifteen miles in the opposite direction, although the 

 latter is a place peculiarly susceptible to earthquakes. '-■• 



Mr. Dodge's stirvey made 011 July 30th (Fig. 118) shows the changes wrotight 

 in Halemaumau that Mr. Thurston has so graphicall}- described. The figures both 

 on the plan and sections are the distance below the Volcano Hotise datum. 



Auo;ust 7, iSg^. Walter F. Frear. — The lake was active, the largest fountain (Old Faithful) 

 jilaying once or twice a minute, coming up each time as one, two or three bubbles, and then being- 

 quiet until the next burst ; the other fountains, four to six generally at a time, placing often several 

 minutes before quieting down. Old Faithful always played in the same place, this being the same 



place in which it played in March, 

 been in the same place ever since. 



'92, when I saw it on four different days. The guide says it has 

 The other fountains were not confined to any particular locality. 

 Aside from the surface appearance of the lake, 

 there were at this time three points of special interest, 

 ( I ) the change in height of the lake, (2) the falling in 

 of the sides of the pit, and (3) the floating islands. The 

 guide informed me that the height of the lake and the 

 contour of the walls of the pit were substantially the 

 same on July 24 as just after the drop of July 11. This 



was apparently so There was no change in the 



height of the lake and no falling in of the sides from the 

 24th until after the 27th. On the 2Sth and 29th there 

 was much falling in of the sides, as shown by frequent 

 clouds of dust, and on the 30th I noticed that the lake 

 had fallen about fifteen feet. On August 2d there was 

 also much falling in, and on August 4th I noticed that 



the lake had fallen about twenty feet more 



The guide said that two large islands made of pieces of fallen cliff had drifted at the time of 

 the drop and become fastened, one to the north wall, the other to the south wall. These were still 

 large on the 24th, but had mostly melted away by August 4th. There was one large island near 

 the middle of the lake each time I went down. The first three times I could not see the whole 

 of it from any one point from which I looked at it. On the 30th I got a good view from another point. 

 Its shape was as in Fig. 117. Its length, .\-b, was perhaps a hundred and thirt>- feet, its height 

 at B about eight feet, at A about twelve or fifteen feet, and at c eighteen to twenty feet. Its surface 



Fig. 117. OUTLINE OF ISLAND IN I.AKK. 



'Thrum's Animal, 1.S95, p. 78. 



[567] 



