100 NATURAL SCIENCE. 



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. 12mp. Cloth. 

 viii + 353 pages. With a color chart of spectra, etc. Mailing price, 

 $ 1.10; for introduction, $1.00. 



rpHE constantly 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 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 mak- 

 ing electrical measurements with inexpensive apparatus, the com- 

 pound 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 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 suited to the grades that will use the book. 

 The experiments are of practical significance, and simple in manip- 

 ulation. ^The Introduction is even more fully illustrated than the 

 Elements. 



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 gild- 



