576 



SCIENCE. 



[N. S. Vol. XXI. No. 537. 



be handled rather frequently by many of its 

 owners. 



Edwin B. Frost. 



Yerkes Observatory. 



La Montague Pelee et ses Eruptions. Par A. 

 Lacroix. Ouvrage Public par 1' Academic 

 des Sciences sous les Auspices des Minis- 

 teres de I'lnstruction publique et des Colo- 

 nies, Paris. 1904. Pp. xxii + 662. 30 

 plates and numerous text figures. 

 The most complete report on Martinique yet 

 published is that of Professor Lacroix, which 

 embodies the results of his researches during 

 two extended sojourns in the West Indies. 

 Few geologists were better qualified to under- 

 take the task and unusual facilities were of- 

 fered him to make as exhaustive an examina- 

 tion as the conditions would permit of the 

 volcano Pelee. 



Professor Lacroix was sent, at the sugges- 

 tion of the Academic des Sciences, by the 

 Minister of the Colonies at the head of a 

 scientific commission to study the effects of 

 the eruption of Pelee and to examine into its 

 causes. The commission consisted, in addi- 

 tion to Professor Lacroix, of M. Rollet de 

 I'Isle and M. Giraud. After a preliminary 

 visit of little more than a month in June and 

 July, 1902, the party returned to France to 

 arrange for a longer visit in the dry season. 

 The eruption of the thirty-first of August 

 hastened Professor Lacroix's departure ^and 

 he arrived a second time at Fort de France on 

 the first of October alone, the other members 

 of the mission being unable to accompany 

 him. During this second visit, which lasted 

 nearly six months, the greater part of the 

 material was gathered upon which the present 

 report is based. 



Two observatories were established from 

 which the volcano could be watched day and 

 night, and at these posts were cameras and 

 various instruments for the purpose of record- 

 ing with as minute detail as possible all 

 events, or changes in the form of the moun- 

 tain. The results of these observations were 

 correlated by Professor Lacroix, who devoted 

 a greater part of his own time to an examina- 

 tion of the volcano, the collection of speci- 



mens, and to obtaining, if one may judge from 

 the illustrations of the book, a large number 

 of very remarkable photographs. 



In presenting his results Lacroix has ar- 

 ranged them under three heads : The first part, 

 which is by far the longest, deals with the 

 geological and physical problems involved in 

 the eruptions, and contains detailed descrip- 

 tions of the more violent outbreaks. The 

 second part is devoted to a petrographical 

 study of the actual products of the eruption 

 and to a comparison of these with rocks from 

 the other islands of the Lesser Antilles. In 

 the third part, the various products resulting 

 from the conflagration of Saint Pierre are dis- 

 cussed, particular attention being paid to the 

 secondary minerals developed and the effect of 

 intense heat on the old andesite of which most 

 of the houses were built. 



Much of the information contained in the 

 first part will be familiar to those who have 

 followed Lacroix's earlier reports and the de- 

 scriptions of the American observers, but cer- 

 tain chapters are of unusual interest to geolo- 

 gists, especially those which deal with the 

 processes involved in the formation of the 

 famous ' dome ' and ' spine,' the theory of the 

 ' burning clouds ' (nuees ardentes) of the 

 more violent eruptions, the deposits of frag- 

 mental materials, and the various secondary 

 phenomena. After summarizing in chapter I. 

 of the first part the geology of Martinique and 

 the other Antillean islands, and describing 

 earlier eruptions, the author calls attention 

 in chapter II. to the single center of eruption 

 and the absence of secondary vents. A study 

 of the modifications in topography resulting 

 directly from the great eruptions shows them 

 to have been relatively slight, from a geolog- 

 ical point of view, when compared with the 

 devastation wrought. Judging from the rec- 

 ords of cable repair ships no marked changes 

 in submarine topography occurred and the 

 breaking of the cables is attributed to the 

 shelving of deltas at the mouths of streams 

 descending from the flanks of Pelee. 



In chapter III. Lacroix describes the evolu- 

 tion of the ' dome ' and offers an explanation 

 of the processes involved in its development. 

 Briefly, the ' dome ' is the eminence which has 



