April \, 1872] 



NATURE 



441 



earth ; whilst at the same time the very excellent descrip- 

 tions of the phenomena attendant on vulcanic outbursts in 

 their different phases, and the building up of cones and 

 mountain chains, are of the greatest value to the student, 

 and the more so from their being, in many instances, 

 founded upon the personal experiences of the authon 

 whose accuracy as an observer in the field can only be 

 fully appreciated by those who, like the writer of this 



notice, have had an opportunity of following in his foot- 

 steps, and examining on the spot localities which Mr. 

 Poulett Scrope has so well described in his memoirs. 



In the present volume, the illustrations which are so 

 necessary to a work of this character are not only ample, 

 but are in many instances particularly well selected, so as to 

 express exactly what the author intends to convey. As an 

 example, the following woodcuts. Figs, i and 2, borrowed 



i,^:ri)3^ 



from page 31 of the volume, which represent, in elevation 

 and plan, the volcanic Island of Stromboli, or so- called 

 Lighthouse of the Mediterranean, convey to the mind at a 

 glance the main features of a volcanic cone with its crater, 

 of which, as is so common, the one side of the lip 

 has given way. We may also refer especially to two 

 other woodcuts, Figs. 60 and 61, page 232, as an instance 

 of the e.xtremely happy way in which a comparison is made 

 visible to the eye between the principal features of a 

 region of terrestrial volcanic activity, and those of a por- 

 tion of the visible surface of the moon, in order to point 



C 



out in the wor^^s of the author (p. 231) that "the analogy 

 is so close, that it is impossible for a moment to doubt the 

 volcanic character of the lunar enveloping crust." 



The perusal of this volume, however, also shows that 

 the mineralogy or petrology of volcanos is but barely 

 touched upon, and that the work in reality treats only of 

 one half of the subject under consideration, giving only 

 the purely physical or mechanical, whilst it leaves out of 

 consideration the other half, or equally important chemi- 

 cal one, in which so much has been done during the last 

 twenty years,and without the due consideration of which, it 



is self-evident that no confidence can or ought to be placed 

 in conclusions drawn as to the causes, probable seat of, or 

 many other questions relating to volcanic action, or to the 

 nature of the interior of the earth itself, which is so in- 

 timately connected therewith ; and it is on this account 

 that we have purposely abstained in the present notice 

 from criticising the theoretical views and deductions of 

 the author. 



In conclusion, whilst we, for the reasons before 

 mentioned, heartily recommend Mr. Poulett Scrope's 

 " Volcanos" to the mature consideration of every English 

 student in this branch of geology, we at the same time 

 advise that it should be studied in connection with the 

 admirable memoirs of Bunsen, v. Waltershausen, and 

 others, which have of late years thrown so much light 

 upon the nature of volcanic phenomena, in order that by 

 making himself conversant with the two great forces in 

 Nature, physical and chemical, he may be the better en- 

 abled to arrive at sound conclusions. 



David Forbes 



OUR BOOK SHELF 



Quarterly Weather Report of the Meteorological Office. 

 Part 111. July to September 1870. (Stanford, 1872.) 

 This, the new number of the Quarterly Weather Report, 

 is in point of care the equal, in some minor details of 

 execution the superior, of all former numbers. The 

 method of showing the wind's velocity by a shaded curve, 

 which has been aaopted since the first part of this series, 

 adds much to the ease with which the graphic representa- 

 tion can be read, and is a decided improvement; so is 

 the introduction into the margin of the miniature charts of 

 barometric pressure during strong winds. The engraving 

 too is clearer and finer than in some of the past numbers, 

 and is perhaps as nearly perfect as can be. After a few 

 years the accumulated numbers of these reports will form 

 a most valuable record. There are many students of 



