20 J. D. Dana — History of the Mi Loa Summit Crater. 



200 to 700 feet, and rarely below 300 feet ; diameter of the 

 fountain. 100 to 300 feet, " and rarely perhaps reaching 400 

 feet.'* The jet of fire sometimes shot up into a tapering gothic 

 spire of 700 feet, then rose in a grand mass 300 feet in diam- 

 eter, but varied at top with points and jets like the ornaments 

 of gothic architecture. He adds that to appreciate the most 

 terrific element in the sublime composition you should stand 

 at the foot of a Niagara, or on a tempest-lashed shore ; for 

 "the force necessary to raise 200,000 to 500,000 tons of lava 

 at once into the air would not be silent in its operation." The 

 lava stream is stated to have a depth, in some places, of 200 or 

 300 feet. 



1855, Aug. 11. — During the evening of August 11, a glow- 

 ing point of light was seen at a height of 12,000 feet on the 

 northeast slope of the mountain.* The light rapidly extended, 

 and it soon became evident that a lava-stream was on its way 

 down the mountain. Xo earthquake had announced the erup- 

 tion. 



Mr. Coan ascertained, through his excursions, that a line of 

 fissures extended from near the summit for five miles down 

 the northeast side to the place of outbreak, along which 

 there were cones of volcanic scoria and sand 100 feet or so 

 high, that had been thrown up at the points of greatest activ- 

 ity. Descending the mountain, the cones became lower and 

 less frequent, and were the ragged jaws of orifices through 

 which the stream of lava was visible. 



The place of outflow was a crater formed over a fissure two 

 to thirty yards wide. The lava flowed in a continuous stream 

 down slopes of all angles from less than one degree to verti- 

 cally. The course was eastward like that of 1852, and it 

 finally stopped within five miles of Hilo. 



Mr. Coan describes the tunnels in the lava stream, and speaks 

 of the lavas seen through openings, as moving with great 

 velocity — " estimated to be 40 miles an hour." Some of the 

 steaming openings were 30 to 200 feet long, and the flowing 

 lavas were 50 to 100 feet below. But the progress of the front of 

 the stream, where were obstructions of trees, jungles, depres- 

 sions, etc.. was "slow — say one mile a week." He observes 

 that owing to the cooling, and the partial damming thereby 

 along the front, the hardened upper stratum was raised by the 

 descending stream into numerous tumuli of various forms and 

 sizes as if by pressure from above, which became cones or 

 domes, and let out lavas to flow over the surface and add to the 



*Coan, this Journal. II, xxi, 144, 139, 1856, letters of Sept. 27 and Oct. 15, 

 1855: ibid., p. 237, letter of Xov. 15. 1855; ibid., xxii. 240, letters of March 7, 

 1856 : ibid., radii 435. 1857, letter of Oct, 22, 1856 : Life in Hawaii, p. 289. 



