﻿520 Revieivs — Harrison's Geology of Leicester and Rutland. 



to the poles, and compelling precipitation to take place on the slopes 

 nearest the equator, and thus, by continual accumulation, would 

 these mountains of ice creep far into the temperate zones ; whilst at 

 the poles themselves there would probably be less ice than is found 

 there at the present day. 



This wholesale accumulation of ice at the poles, of course, implies 

 a like abstraction of water from the sea, and Mr. Belt calculates that 

 a lowering of the sea-level to the extent of 2000 feet took place all 

 over the world. 



The author agrees entirely with Prof. Tyndall, that to reduce the 

 force of the sun's rays would cut the glaciers off at their source, and 

 that " we cannot afford to lose an iota of solar action ; we need, if 

 anything, more vapour, but we need a condenser so powerful that 

 this vapour, instead of falling in liquid showers to the earth, shall 

 be so far reduced in tempei'ature as to descend in snow." ^ This con- 

 denser, Mr. Belt maintains, exists within the Antarctic circle, which, 

 as it moved northward, intercepted the vapour to be condensed in 

 increased quantities. 



As now-a-days polar ice is kept within proper bounds by the 

 countei"balancing forces of nature (as Mr. Belt admits, p. 2^), it 

 must be left for physicists to decide on the causes that led to its ex- 

 traordinary behaviour during the so-called " Glacial Period." 



B. B. W. 



II. — A Sketch of the Geology of Leicestershire and PlUtland. 

 By W. J. Harrison, F.G.S. Eeprinted from White's History, 

 Gazetteer, and Directory of the Counties. Large 8vo. pp. 67. 

 (Sheffield, 1877.) 



SKETCHES of the Geology of our English counties are always 

 welcome. The residents who have any taste for the science 

 naturally take especial interest in the geology of their own county, 

 and to many of them, as well as to the occasional visitor, a work in 

 which the principal facts are narrated is a great boon, because 

 many have neither time, inclination, nor opportunity to study the 

 numerous special papers that may have been written upon the 

 subject. 



Mr. Harrison has already done much useful work in this way by 

 preparing a series of Outlines of the Geology of the Counties of 

 England, many of which have appeared in Kelly's Post-Ofifice 

 Directories for 1876 and 1877. And he has now given us a far 

 more elaborate sketch of the Geology of Leicestershire, accompanied 

 by a short account of Kutland, which counties, from his position as 

 Curator of the Town Museum at Leicester, he has had ample oppor- 

 tunity of investigating. 



Leicestershire, geologically speaking, is one of our most interest- 

 ing counties. In it we are brought face to face with some of the 

 grander problems of , Geology, as offered for solution in its tiny 

 mountain-group of Charnwood Forest, where some of the older 



1 Heat as a Mode of Motion, p. 188. 



