VULCANOLOGY AND SEISMOLOGY. 291 



tbiuks that the eruption ''was a purely liydrotliermal phenomenon, 

 but on a gigantic scale." An illustrated popular account of Ibis erup- 

 tion by C. F. Gordon Cummiug may be found in "The Leisure Hour," 

 October, 1S86. 



The changes that have occurred in the Hawaiian volcano of Kilauea 

 during 188G are of interest. On the evening of March 6, 1886, the lakes 

 of liquid lava in- this great pit crater were unusually active, but after 

 midnight of that night the lava suddenly sank away, leaving the site 

 of Halemaumau a great hole 500 feet deep. No overflow of lava oc- 

 curred above the sea-level, although several rents were made outside of" 

 the crater. There may have been a submarine discharge (Am. Jour. 

 Sci., XXI, •■)97). Soon after this occurrence the crater was visited by J. S. 

 Emerson, of the Hawaiian Government Survey, who remained there 

 from March 2-1 to April 14. During his stay no molten lava was any- 

 where visible in the entire crater, although there were evidences of heat 

 beneath the surface. He describes Halemaumau as a pit 600 feet in 

 diameter and 275 feet deep. He made surveys of the crater and inferred 

 that the lava which had disappeared had "found its way into the great 

 fissures of 1868, and from the spongy nature of the district had readily 

 found all the space needed to contain its entire volume without coming 

 to the surface or entering the sea." (Am. Jour. Sci. xxxiii, 87.) About 

 three months later L. L. Van Slyke remained at Kilauea from July 19 

 to 24. At that time the deep pit observed in April was replaced by a 

 conical hill of loose rocks, some 150 feet high. Molten lava was also 

 again visible in places, one being at the bottom of "a deep hole or well, of 

 rather irregular outline, four-sided, perhaps 30 or 40 feet wide and from 

 60 to 75 teet long, and not less than 100 feet deep." (Am. Jour. Sci., 

 XXXIII, 95.) Again, at the beginning of October, it was visited by F. S. 

 Dodge, who describes the pit of Halemaumau as now occui)ied by an. 

 irregular pit or lake, surrounded by a range of hills or ridge nearly cir- 

 cular in form and about 1,000 feet across. There appeared to be fire in 

 the central pit, although he could not get near enough to actually see 

 into It. (Am. Jour. Sci., xxxiii, 98.) 



A volcanic eruption was reported to have occurred in the island of 

 Nina Foou, one of the Friendly Islands, beginning August 31, 1886, and 

 continuing ten days, covering the greater part of the island with stones 

 and ashes to a depth of 6 to 9 meters, killing the vegetation and de- 

 stroying all the villages but two, with, however, but little loss of life. 

 (Humboldt, 1887, p. 116.) It is noticed that the date of this eruption is 

 the same as that of the Charleston earthquake (Nature, xxv, 127), but 

 Professor Dana does not regard this as any reason for supposing a con- 

 nection between the two. He notices the similarity in general direction 

 of these islands with that of the volcanic line of central New Zealand 

 (N. 30O E.), and thinks that this line, 1,500 miles long, " may be viewed 

 as having been, at the beginning and since, the course of a series of 

 fractures and a line of common genetic action," which would tend to 



