788 
Analyses of Books. 
[December, 
Blue,” “ Summer Meadows,” and “ Hedge Garlands.” Dr. 
Taylor is by no means the “ dry ” man of science whom the out- 
side world regard with such horror. He has a keen eye and a 
loving heart for whatever is beautiful in Nature, and his book 
will, therefore, prove a pleasant companion. 
Elements of Astronomy. By R. S. Ball, LL.D., F.R.S., Royal 
Astronomer of Ireland. London : Longmans, Green, and 
Co. 
This book, though mainly intended for beginners, is a scientific, 
not a popular treatise. The author not merely avoids the oppor- 
tunities for somewhat sensational contemplation which his sub- 
ject affords, but his physical descriptions of the nearer and better 
known heavenly bodies are kept well within the limits of what is 
actually demonstrable. Thus, in treating of Jupiter, he leaves to 
other works the consideration whether this huge planet is or is 
not, in addition to the light received from the sun, slightly self- 
luminous, nor does he discuss the question of the solid or molten 
character of its globe. For the physical theory of comets he also 
refers the reader to the well-known researches of Professor 
Zollner. 
T e work opens with an account of the principal astronomical 
instruments, the method of their use, and the phenomena to be 
observed. The evidence for the approximately spherical form of 
the earth and for its diurnal and annual motions are given with 
great clearness, and the various terms used by astronomers, such 
as right ascension and declination, polar distance, &c., are ex- 
plained. Dr. Ball then considers the sun, its apparent motion, 
solar observations, apparent diameter, path in space, velocity, 
dimensions, sun-spots, &c. In successive chapters the motion 
of the earth round the sun, the moon, the planets, comets, and 
meteors, universal gravitation, stars and nebulae, and the 
structure of the sun, are considered in turn. The remainder of 
the book is devoted to astronomical constants. A useful feature 
consists in the references to more extensive or to special works 
subjoined to many of the sections. 
Dr. Ball avoids the error of many writers on astronomy who 
pre-suppose on the part of their readers very profound mathe- 
matical attainments. A knowledge of the elements of Euclid 
and Algebra, and a rudimentary acquaintance with the geometry 
of planes and spheres, is sufficient for a thorough understanding 
of this book. It has the high merits of clearness, simplicity, and 
soundness. 
