520 Reviews— 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 dav. 
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 sliowers to the earth, sliall 
be so far reduced in temperature as to descend in snow.” 1 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 
counterbalancing forces of nature (as Mr. Belt admits, p. 2 3 ), it 
must be left for pliysicists 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 Rutland. 
By W. J. Harrison, F.G.S. Reprinted from White’s History, 
Gazetteer, and Directory of the Counties. Large 8vo. pp. 67. 
(Sheffield, 1877.) 
S KETCHES 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, 
arid 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 opportiinity 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-Office 
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 Rutland, which counties, from his position as 
Curator of the Town Museum at Leicester, he has had ample oppor- 
tunity of investigating. 
Leicestershire, geoiogically 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. 
