Reviews, — Dr. Johnston- Laris — Earthquakes of Ischia. 369 



Ireland, and three forms, Gaudryina Jonesiana, Bolivina decorata, and 

 Marginulina Beussiana, are new to science. The new forms, as well 

 as some others, are figured in the plate accompanying the memoir. 



a j. h. 



BBVIE "W S. 



I. — Monograph of the Earthquakes of Ischia. A Memoir 

 Dealing with the Seismic Disturbances in that Island 

 from eemotest tlmes, with special observations on those 

 of 1881 and 1883. By H. J. Johnston-Lavis, M.D., F.G.S., 

 etc., and Some Calculations by Rev. Prof. Samuel Haughton, 

 M.D., F.R.S. 4to. pp. 112. With numerous Plates and Photo- 

 graphs. (F. Furchheim, Naples ; Dulau & Co., London, 1885.) 



IN this work Dr. Johnston-Lavis has essayed to do for the recent 

 earthquakes of Ischia that which was so well accomplished for 

 the great Neapolitan earthquake of 1857 by the late Mr. Eobert 

 Mallet. In the mathematical portion of the work he has been 

 fortunate in securing the co-operation of Dr. Haughton, who supplied 

 Mr. Mallet with the necessary equations for his work. 



The excellent way in which Dr. Johnston-Lavis made use of his 

 opportunities as a resident in the neighbourhood, after the earthquakes 

 of 1881 and 1883, is very well known ; and the columns of Nature 

 and various newspapers were supplied with detailed accounts of 

 catastrophes from his pen, many of which contain observations 

 of considerable scientific value. But in the present work, he has 

 treated the whole subject in a systematic and comprehensive manner, 

 and has succeeded in producing a book which, like that of Mallet, 

 is of great value both to seismologists and geologists. 



After a short introductory chapter, the author devotes six pages to 

 a resume of what is known concerning the geology of Ischia, based 

 on the researches of Scacchi, Fonseca, Vom Rath, Fuchs, and other 

 geologists. Chapters III. and IV. are chiefly historical ; the former 

 dealing with the earthquakes and eruptions which have occurred in 

 the island from the earliest historical times down to the present day ; 

 while the latter contains a translation of Covelli's interesting account 

 of the Ischian earthquake of February 2nd, 1828. Chapters V. and 

 VI. are occupied with the details of the author's own observations 

 on the effect of the earthquakes of March 4th, 1881, and of July 

 28th, 1883, respectively. The destructive effects of these great earth- 

 quakes are made strikingly apparent to every one, and especially to 

 those who have visited the island, by the series of admirable photo- 

 graphs, taken for the most part by the author himself, and repro- 

 duced for the purpose of this work in Turin. 



The next three chapters of the book are devoted to a discussion of the 

 nature of the earthquake waves, and of the paths which they followed, 

 and to a determination of the positions of the seismic vertical, 

 the epicentra, and the isoseismals of the two earthquakes ; while, 



DECADE III. VOL. III. NO. VIII. 21 



