100 NATURAL SCIENCE. 



Introduction to Physical Science. Revised Edition. 



By A. P. Gage, Instructor in Physics in the English High School, 

 Boston, Mass. 12mo. Cloth, viii + 374 pages. -With a color chart ol 

 spectra, etc. Mailing price, fl.lO ; lor introduction, $1.00. 



T^HIS work has this distinct and distinctive aim, — to elucidate 

 science, instead of "popularizing" it; to make it liked for 

 its own sake, rather than for its gilding aud coating; and, while 

 teaching the facts, to impart the spirit of science, that is to say, 

 the spirit of our civilization and progress. 



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

 It is believed that this revised edition of 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. 



The size and general features of the book in its present revised 

 form have been changed little, but numerous slight changes have 

 been made throughout the work which will be found improvements 

 and which will make it more acceptable to those using it. 



The departments of Electricity and Mechanics, however, have 

 been entirely re-written and will challenge comparison with any 

 text-book of its size extant. 



Some important changes have been made in the last part of 

 the chapter on Light. 



Several new topics have been introduced into the chapter on 

 Heat, notably the sections on Specific Heat and Absolute Tem- 

 perature. 



Some important additions have been made to the Appendix. 

 These are chiefly in the way of enlarging upon certain subjects 

 (for instance, the Pendulum, Expansion Coefficients, the Dynamo, 

 the Electric Motor) for the benefit of those who would pursue 

 these subjects to a greater extent than the scope of a very elemen- 

 tary text would warrant. The main text has been increased only 

 about fifteen pages, but, with the changes and additions made, 

 the teacher should find no difficulty now in fitting pupils for 

 Harvard or any other American college. The style will be found 

 suited to the grades that will use the book. 



