266 



NATURE 



[July 17, 1890 



such amendment as shall secure evidence of a reason- 

 able degree of capacity for science on the part of every 

 probationer, whilst it would be well also if it could be 

 made to encourage a rather wider range of literary study 

 in the earlier education of those whose main interests 

 lie in the direction of science. What is desirable 

 could be attained in several ways. But it could, perhaps, 

 be best effected by permitting candidates to offer them- 

 selves for examination in three subjects instead of two 

 from Class II. ; with the limiting condition that one at 

 least of these three must be taken from numbers 5, 6, 7, 8, 

 and one of them from 9, 10, 11, 12. 



We trust that this subject may also be brought under the 

 notice of the authorities at the India Office. It seems 

 evident from the changes already made that they are in 

 no way prejudiced against either scientific or literary 

 studies, and we feel sure that if they will institute inquiries 

 they will find that similar opinions to those we have 

 expressed are widely held on this subject. 



THE VOLCANOES OF HA WAH. 

 Characteristics of Volcanoes^ with Contributions of Facts 

 and Principles from the Hawaiian Islands : including 

 a Historical Review of Hawaiian Volcanic Action for 

 the past Sixty-seven Years, a Discussion of the Relations 

 of Volcanic Islands to Deep-sea Topography, and a 

 Chapter on Volcanic-Island Denudation. By James 

 D. Dana. Illustrated by Maps of the Islands ; a 

 Balhymetric Map of the Atlantic and Pacific Oceans ; 

 and Views of Cones, Craters, a Lava-Cascade, a Lava- 

 Fountain, &c. (London : Sampson Low, Marston, 

 Searle, and Rivington, i8go.) 



THE veteran geologist of the United States has 

 rendered an inestimable service to science by the 

 publication of this splendid monograph, which has just 

 made its appearance simultaneously in this country and 

 in the United States. To find any work on a similar 

 subject comparable with it either in importance, or in 

 the influence it is likely to exert upon geological thought, 

 we must go back to the publication of Fouqu^'s 

 " Santorin," of Von Waltershausen's " Etna," or Scrope's 

 " Volcanoes of Central France." 



The Hawaiian volcanoes are unquestionably the grandest 

 on the face of the globe. Their vast dome-shaped masses, 

 with slopes averaging from 6° to 8°, rise to heights of only 

 •14,000 feet above the sea-level ; but deep-sea soundings 

 have shown that they stand on a floor i2,coo to 18,000 

 feet below that level, so that, as Prof. Dana points out, 

 the higher volcanic mountains of the Sandwich Islands 

 must have an elevation of not far from 31,000 feet 

 above their bases ! Beside these lofty and bulky 

 domes, the graceful volcanic cones of the North and 

 South American continents, of Japan and Java, sink into 

 insignificance. The Hawaiian Archipelago contains no 

 less than fifteen volcanoes of the first class, all but three 

 of which appear to be now extinct. The active volcanoes 

 of Hawaii give rise to lava-floods, which, in their bulk and 

 in the distances they flow from their point of emission, 

 are only surpassed by those of Iceland. In their remark- 

 ably non-explosive action, in the characters of their great 

 pit-craters, in the wonderful liquidity of their lavas — giving 

 rise to veritable fountains of molten rock — and in the 

 beauty and singularity of some of their igneous products, 

 NO. 1 08 I, VOL. 42] 



the Hawaiian volcanoes are without a parallel anywhere 

 else in the world. 



The Hawaiian volcanoes appear to form two nearly 

 parallel bands, which doubtless indicate great lines of 

 fissure in the earth's crust, the extreme length of these 

 being about 400 miles. The recent topographical surveys 

 of the islands made by Prof. W. D. Alexander, Surveyor- 

 General to the Hawaiian Government, and a number of 

 recent soundings in the adjoining seas, enable us to realize, 

 in a way that was not previously possible, the dimensions 

 and forms of these vast volcanic piles. 



Prof. J. D. Dana has enjoyed exceptional facilities for 

 studying these unique centres of igneous activity. As 

 naturalist of the U.S. Exploring Expedition, he visited 

 the islands in November 1840, after the great eruption of 

 Kilauea that had taken place in May of the same year. 

 The work of the actual survey and description of the 

 craters was unfortunately not committed to Prof. Dana ; 

 for the energetic, though scientifically untrained, head of 

 the Expedition, Captain Wilkes, determined to undertake 

 this task himself ; and the naturalist was sent away to 

 another station while the survey was in progress. Had 

 Prof. Dana been present to advise and assist the survey- 

 ing officers, it is clear that many unfortunate errors would 

 have been avoided, and that the accounts of the volcanoes 

 contained in the " Narrative of the United States Ex- 

 ploring Expedition" would have had far greater scientific 

 value. 



After his return to the States and his settlement at Yale 

 College, Prof Dana showed his continued interest in the 

 Hawaiian volcanoes, by keeping up a constant corre- 

 spondence with missionaries and other residents in the 

 islands ; and every great eruption was carefully chronicled 

 in the pages of the A7nerican fournal of Science, which 

 he has so long edited. The memoirs of Brigham and 

 Captain Dutton, and the enlargement and correction of 

 our topographical knowledge of the islands, resulting 

 from the Government survey, seem once more to have 

 aroused the author to a sense of the importance of the 

 subject, and in 1887 he commenced a series of papers on 

 the history of the changes in the Mount Loa craters. He 

 had not proceeded far with this work, however, before he 

 felt the need of a second personal examination of the 

 district. With characteristic energy, he undertook, in 

 spite of his advancing years, a ten-weeks' journey, in- 

 volving over ten thousand miles of travel, in which he 

 visited all the chief points of interest ; and the book 

 before us is the outcome and monument of his labours. 



The work of criticizing and reconciling the accounts 

 given by numerous travellers, beginning with notices 

 written as long ago as the year 1823, has been admirably 

 performed by Prof Dana. Without his personal knowledge 

 of the localities, and the aid afforded by the new and accu- 

 rate maps of the islands, the task would, indeed, have been 

 a hopeless one ; for many of the descriptions were penned 

 by unscientific and careless writers, and inaccuracies and 

 exaggerations are encountered at every step. By sifting 

 and correlating this confusing mass of evidence, how- 

 ever, the author is able to give a clear and connected 

 narrative of the changes in the Kilauea crater, and to 

 illustrate the position of its floor after each of the great 

 eruptions, which took place in 1823, 1832, 1840, 1868, 

 and 1886. The result is that we are furnished for the 



