TWENTIETH CENTURY TEXT-BOOKS. 



PHYSICS. 



Elements of Physics. 



By C. Han ford Henderson, A. M., Ph. D., and John 

 F. WooDHULL, Ph. D., Professor of Physics in Teachers 

 College, Columbia University. i2mo. Cloth, fi.io. With 

 Experiments, $1.25. 



Physical Experiments : A Laboratory Manual. 



By John F. Woodhull, and M. B. Van Arsdale, 

 Instructor in Physical Science in Horace Mann School and 

 Assistant in Teachers College. i2mo. Cloth, 45 cents ; 

 with alternate blank pages, 60 cents. 



Inexpensive Apparatus. The figures used to illustrate these 

 books and the apparatus recommended in them are comparable to 

 maps that show only the matter under consideration and leave out the 

 things that confuse, divert, and obscure. 



Self-Explanatory. The text-book is not a syllabus of rules as 

 an adjunct to laboratory experiments, nor merely a table of reference, 

 but is self-explanatory and " readable " in the best sense, its literary 

 style being lucid, fresh, warm, and attractive. Hence it gives the sub- 

 ject a live interest. 



Laboratory Work. The laboratory manual is something more 

 than a book of directions for laboratory work. It is full of suggestions 

 of facts and phenomena in nature parallel with the experiments. 

 Problems are very abundant, drawn largely from sources within the 

 pupil's own experience, and intended to lead the pupil to organize his 

 thoughts in connection with his laboratory work. 



Special Chapters. The treatment of electricity in these books 

 ij particularly clear and simple. It treats of the telegraph, the electric 

 bell, the electric light, the motor, the dynamo, electric cars, telephone, 

 wireless telegraphy, Roentgen rays. etc. The chapters on Mechanics, 

 Heat, Light, and Sound also areremarkably interesting as well as 

 highly instructive. 



Portraits of eminent scientists and brief statements concerning 

 their fives and labors make the study more attractive by giving it a 

 concrete human aspect. 



The texf-book and laboratory manual meet perfectly ever^ 

 deta'l of college-entrance reauirements. 



D. APPLETON AND COMPANY, NEW YORK. 



