IS79-J 
Notices of Books. 
hi 
and Refraction of Plane Waves ; General Equations ; Application 
of General Equations ; the Theory of Resonators ; Application 
of Laplace’s Functions; Spherical Sheets of Air, and Motion 
in Two Dimensions ; Fluid Friction, and the Principle of Dyna- 
mical Similarity. The whole subjedt is treated with consummate 
ability, and the work affords a complete mathematical treatment 
of the subjedt. 
The Moon, her Motions, Aspect , Scenery, and Physical Condition . 
By Richard A. Proctor. Second Edition. London : 
Longmans. 1878. 
In the second edition of this popular work the author has 
omitted a good many calculations, connedted with the lunar 
theory, which were too difficult for the general reader. He pro- 
poses to reprint these in a separate volume on the “ Geometry 
of the Lunar Theory,” for the use of those who are acquainted 
with the higher mathematics. Otherwise this edition does not 
differ much from the preceding, except that the final chapter, on 
the moon’s physical condition, has been enlarged. We may 
remind our readers that the author discusses in succession the 
size, mass, and distance of the moon ; her motions and changes 
of aspedt, and a complete study of the surface so far as it is 
known. In the chapter on Lunar Celestial Phenomena the lunar 
atmosphere, scenery, seasons, and eclipses are described. The 
author considers that the “ moon was shaped, so to speak, when 
the solar system itself was young, when the sun may have given 
out a much greater degree of heat than at present, when Saturn 
and Jupiter were brilliant suns, when even our earth and her 
fellow minor planets within the zone of asteroids were probably 
in a sun-like condition.” He inclines also to the belief that the 
process of contraction which the moon’s surface underwent pro- 
duced the processes of disturbance which have resulted in the 
present condition of the moon’s surface. An admirable map of 
the moon, after Beer and Madler, is given at the end of the 
volume, and some striking illustrations of the condition of the 
moon’s surface are taken from Nasmyth and elsewhere. Alto- 
gether the work furnishes a very popularly written, and at the 
same time exadt, account of the moon, and we are sure that it 
will continue to be largely read both by the scientific and the 
ordinarily well-educated reader. 
