NATURAL SCIENCE. 93 



Introduction to Physical Science. 



By A. P. GAGE, Instructor in Physics in the English High School, Bos- 

 ton, Mass., and Author of Elements of Physics, etc. 12mo. Cloth, 

 viii + 353 pages. With a chart of colors and spectra. Mailing Price, 

 $1.10 ; for introduction, $1.00 ; allowance for an old book in exchange, 

 30 cents. 



rriHE great and constantly increasing popularity of Gage's Ele- 

 ments of Physics has created a demand for an equally good 

 but easier book, on the same plan, suitable for schools that can 

 give but a limited time to the study. The Introduction to Physical 

 Science has been prepared to supply this demand. 



Accuracy is the prime requisite in scientific text-books. A 

 false statement is not less false because it is plausible, nor an in- 

 conclusive experiment more satisfactory because it is diverting. 

 In books of entertainment, such things may be permissible ; but 

 in a text-book, the first essentials are correctness and accuracy. 

 It is believed that the Introduction will stand the closest expert 

 scrutiny. Especial care has been taken to restrict the use of scien- 

 tific terms, such as force, energy, power, etc., to their proper signifi- 

 cations. Terms like sound, light, color, etc., which have commonly 

 been applied to both the effect and the agent producing the effect 

 have been rescued from this ambiguity. 



Recent Advances in physics have been faithfully recorded, 

 and the relative practical importance of the various topics has been 

 taken into account. Among the new features are a full treatment 

 of electric 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, which is now generally re- 

 garded as of comparatively little importance, is treated briefly; 

 while dynamic electricity, the most potent and promising physical 

 element of our modern civilization, is placed in the clearest light 

 of our present knowledge. 



In Interest and Availability the Introduction will, it is 

 believed, be found no less satisfactory. The wide use of the 

 Elements under the most varied conditions, and, in particular, 

 the author's own experience in teaching it, have shown how to 

 improve where improvement was possible. The style will be found 



