262 
Notices of Boohs. 
[April, 
include the important paper on Conical Refraction ; twelve relate to 
Magnetism; two to Meteorology ; and five are Addresses delivered 
on various occasions, on various subjects. The papers extend over 
many years : we have a Report on the Progress and Present State 
of Physical Optics, which was read before the British Associa- 
tion in 1834; and the Introductory Address delivered before the 
same Association twenty-three years later. The Report on 
Physical Optics extends over 128 pages, and is of much value 
for reference. The magnetic observations go back as far as 
1834., and they were made in conjunction with Capt. Sabine and 
Capt. James Ross. The observations are accompanied by some 
useful charts. The chapters on the Meteorology of Ireland will 
always be valuable, and will no doubt form the basis of a com- 
plete system of meteorological observation, which may hereafter 
be established in the island. The Introductory LeCture, on the 
rise and progress of mechanical philosophy, contains an inte- 
resting historical account of the earlier researches in this branch 
of natural philosophy. Altogether the work will be found of 
great interest to the man of Science. 
Physiography : an Introduction to the Study of Nature. By 
J. H. Huxley, F.R.S. London : Macmillan. 1877. 8vo., 
377 PP- 
This work embodies the subjeCt-matter of a course of educa- 
tional leCtures delivered nine years ago at the London Institution. 
It is a Physical Geography containing the newest and most 
accurate details, and divested of the formal treatment which 
usually characterises works on that subjeCt. The opening chap- 
ter treats of “ The Thames,” and this river was chosen because 
the leCtures were addressed to Londoners by a Londoner; but 
the author points out that any intelligent reader or teacher will 
have no difficulty in transferring the ideas herein expressed from 
the Thames to the river and river-basin of his own district. The 
general formation of rivers is traced, and the nature of water- 
shed and water-parting, land-drainage and springs, is discussed. 
A map shows the principal river-basins and water-partings of 
Great Britain. 
The second chapter is on “ Springs,” the formation of which 
is illustrated by some excellent woodcuts. It is shown that all 
such sources of water owe their origin to the rain which sinks 
into the earth, and descends until it finds an impermeable 
stratum. This naturally leads (Chap. III.) to an account of 
rain and dew. The formation of clouds is discussed, and illus- 
trated by some good chromo-lithographs ; a coloured hyeto- 
graphical map shows the annual rainfall in different parts of 
