342 L. A. Thurston — Recent eruption of Kilauea. 



ing from 25 to 100 feet back from the former edge, and the 

 lower half of the debris slope had been swallowed up in the 

 lake, disclosing the original smooth black wall of the lake 

 beneath at a considerable overhanging angle, making the pro- 

 tile of the lake approximately as in figure 5. 



■« g 



El- 



Fig. 4, Profile view of the lake, July 11, 1894; A B, extreme outer margin; C D, 



inner margin; E F, surface of lake, 8 p. at., July 11 ; C E, debris slope. 

 Fig. 5, Profile at 9 a. m., July 12; C G-, debris slope; G E, solid rock. 



At the level of the lake and half-filled by it was a great cav- 

 ern extending in a southeasterly direction from the lake. The 

 dimensions were apparently 75 feet across and 15 feet from the 

 surface of the lake to the roof of the cave. It could be seen 

 into from the opposite bank for about 50 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 16th, that had continued to rise and fall from 5 to 

 10 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 discharge was taking place there were many 

 slight tremors of the banks, generally resulting in the precipi- 

 tate retreat of the observers from the edge, but although the 

 danger was great the spectacle was so grand and fascinating 

 that the party returned again and again to watch it. 



At the Volcano House two slight earthquakes were felt on 

 the afternoon of the 11th 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, although none were felt 

 at Olaa half-way between, nor at Kapapala, fifteen miles in the 

 opposite direction, although the latter is a place peculiarly sus- 

 ceptible to earthquakes. 



This is believed to be the first discharge of Kilauea in the 

 presence of observers, those prior to 1868 being before the 

 establishment of the Yolcano House, and those of 1868, 1886, 

 and 1891 and several minor ones, all having taken place at 

 night when no one was present. 



