J. D. Dana — History of the Mt. Loa Summit Crater. 21 



thickness; that "upgushings" also occurred through fissures ; 

 and that thus layer was added to layer, increasing the thickness 

 from a few feet to 50 or 100, and also retarding the progress 

 of the stream. One dome on the stream was 100 feet high 

 and 300 in diameter ; and through the fissured top and sides 

 the liquid lavas were visible, and easily reached by the pole he 

 had for measuring the thickness of the cap — 2 to 5 feet. 

 These effects were especially great where the slope was very 

 small. Pressure of the lavas above, and gases or vapors from 

 the burning of trees and other vegetable matter buried by the 

 lavas, are made the causes of the uneven surface of the lava 

 stream. 



The stream, in addition, became widened by the lateral out- 

 gushings, divided into a number of channels, and shifted to 

 the right or left. After flowing freely for a while, the stream 

 often suddenly cooled and hardened along the front and re- 

 mained for several days inactive ; " at length, immense areas 

 of the solidified lava, four, five, or six miles above the extrem- 

 ity, are again in motion, cones are uncapped, domes crack, hills 

 and ridges of scoria move, immense slabs of lava are raised 

 vertically or tilted in every direction." 



On the 22d of October, 1856, the stream was within five 

 miles of the sea-coast north of Hilo, still pushing out and 

 spreading itself. Mr. Coan says that the lavas were even then 

 flowing in the tunnel-ways from the place of outbreak to the 

 lower extremity although no fires were seen — evidently an 

 opinion rather than a direct observation. He argues for the 

 absence of fissures beneath the stream for the supply of lava, 

 from the absence of steaming vents and cones. After 15 

 months, in November, the fires ceased action. The stream in- 

 cludes many square miles of aa and immense fields of pa- 

 hoehoe. 



1859, Jan. 23. — Another great eruption began at this date. 

 Prof. P. C. Haskell (of a party visiting the eruption consisting 

 also of Prof. Alexander and President Beck with) reports* that 

 " smoke " was seen over the summit from Waimea by Mr. 

 Lyons of that place on the 23d. In the evening, lavas were 

 ejected, and the light was bright enough at Hilo, 35 miles east, 

 to read fine print. " No earthquake was felt in any part of 

 the island." But dead fish, apparently parboiled, were found 

 in the sea to the northwestward, both east of Molokai and be- 

 tween Molokai and Oahu. 



* Haskell, this Journal xxviii, G6, 284, 1859. (the latter from letter of June 

 22); xxix, 301. I860, letter of Nov. 5. There are shorter reports by Editor of 

 Commercial Advertiser of Oahu and Rev. L. Lyons, ibid, xxvii, 412, 1859; and 

 Coan, ibid, xxvii. 415, letter of February 2, 1859, and xxix, 302, letter of Nov. 

 25, 1859. W. L. Green, "Vestiges of the Molton Globe." 1887, pp. 163, 270, 280. 



