78 On the Recent Condition of Kilaiiea% * 



served by Mr. Coan flowing into and along it from the great 

 lake. On one occasion, indeed, the glowing stream was seen by ^ 

 hira to phinge in a fiery cataract down a precipice fifty feet in 

 height — presenting a sublime spectacle. By these successive 

 overflows this space had, in 1846, become nearly filled up, and 

 in matiy places the former ^^ canal" was entirely obliterated. 



The Great lake in 1846 was by approximate measurements 

 computed to be about 2400 feet in diameter from N.E, to S.W., 

 and 2000 in the transverse direction. Its surface was nearly on 

 a level with the Black ledge and with that portion of the floor of 

 the crater between it and the ledge. It was surrounded on all 

 sides except the northern or northeastern, by a rim or embank- 

 ment of lava from ten to twenty feet in height, built up apparently 

 by repeated partial overflowings and the marginal deposit of clots 

 and jets of lava thrown up by incessant ebullition — somewhat 

 after the manner of the ridge of ice congealed around a fountain, 

 or accumulated along the margin of a river. On the N.E. the 

 lake was bounded by a high broken and almost inaccessible t 

 of lava, rising at length into the elevated plateau before descri 

 When visited by the Exploring Expedition in 1840, the surface of 

 this lake was between three and four hundred feet below the 

 Black ledge, and measured only 1000 by 1500 feet in diameter. 

 Consequently in six years it had not only increased in size, but 

 it had actually risen in height as much as it had been previously 

 depressed by the outdraining of lavas in the eruption of 184.0. 

 This gradual rising of the solid embankment of the lake con- 

 temporaneously with the lake itself, together with the filling up 

 of the whole interior of the crater, is doubtless to be attributed 

 to the combined effect of repeated overflowings, together with 

 the upheaving agency of subterranean forces. 



The surface of the lake was constantly m a state of gentle ebul- 

 lition, yet in consequence of the rapid cooling, becoming covered 

 ^repeatedly with a thift crust, which crust was again constantly 

 breaking' up, and redissolving in the molten mass. The clots or 

 jets of gory lava thrown up by the escaping gases often ascended 

 from five to fifteen feet, and there was a general motion of the 

 surface of the lake slowly towards the southwest. This motion 

 was observed first on the western side, and afterwards at several 

 different points on the eastern. A large stick of wood thrown 

 on the lake, at a point where the ebullition produced a sort of 

 •eddy or rolling in of the lava, was immediately taken out of 

 '^*ight, but the next instant a more violent ebullition, together 

 with a sudden outburst of flame and smoke told how almost in- 

 stantaneously the stick had been transformed into charcoal 



The surface of the fluid lava was some ten or fifteen feet be- 

 low the top of the embankment, and inaccessible by any means 

 at our command for dipping it up. The spectator, however, 



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