NATURAL SCIENCE. 103 
Introduction to Physical Science. 
By A. P. Gacg, Ph.D., Instructor in Physics in the English High School, 
Boston, Mass. 12mo. Cloth. viii+353 pages. With a color chart of 
spectra, etc. Mailing price, $1.10; for introduction, $1.00. 
HE long-continued increasing popularity of Gage’s Elements of 
Physics has created a demand for an easier book, on the same 
plan, suited to schools that can give but a limited time to the 
study. The Introduction to Physical Science meets this demand. 
In a text-book, the first essentials are correctness and accuracy. 
It is believed that Gage’s Introduction will stand the closest expert 
scrutiny. Especial care has been taken to restrict the use of 
scientific terms, such as force, energy, power, etc., to their proper 
significations. Recent advances in physics have been faithfully 
recorded. Among the new features are a full treatment of elec- 
tric lighting, and descriptions of storage batteries, methods of 
transmitting electric energy, simple and easy methods of making 
electrical measurements with inexpensive apparatus, the compound 
steam-engine, etc. Static electricity, now generally regarded as of 
comparatively little practical importance, is treated briefly ; while 
dynamic electricity, the most promising physical agent of modern 
‘times, is placed in the clearest light of our present knowledge. 
The style will be found suited to the grades that will use the 
book. The experiments are of practical significance, and simple 
in manipulation. 
The Introduction, like the author’s Elements, has this distinct 
and distinctive aim, — to elucidate science, instead of “populariz- 
ing” it; to make it liked for its own sake, rather than for its 
gilding and coating ; and, while teaching the facts, to impart the 
spirit of science, that is to say, the spirit of our civilization and 
progress. 
J.P. Naylor, Professor of Physics, 
De Pauw University: In its scien- 
tific spirit, and in accuracy and 
- clearness of statements of  prin- 
ciples, | know of nothing that is its 
superior. 
0. C. Kinyon, Teacher of Physics 
in High School, Syracuse, N. Y.; It 
not only insures an interest in the 
study, but tends to thoroughly arouse 
the powers of observation. 
B. C. Hinde, Professor of Natural 
Science, Trinity College, N.C.: I 
have used Gage’s. It is strictly in 
accord with the best modern teach- 
ing of Physics, 
