Bausch & Lornb 



New Model BH Microscope 



Convenient 

 Durable 

 Inexpensive 



Designed for use in Col- 

 legesandSecondary 

 Schools. 



Handle in the arm 

 permits its being easily 

 carried. 



New construction fine 

 adjustment, very respon- 

 sive and not easily af- 

 fected by continued use. 



All working parts 

 thoroughly protected 

 from dust and dirt. Cir- 



cular 

 proof. 



nose-piece, 



dust 



BH 4, $29-50 



Send for descriptive circular. 



Bausch & Lomb Optical Co., 

 Rochester, N. Y. 



New York, Boston, 

 San frm nciaco, 



Washington, Chicago, 



Frankfurt a M Germany. 



EDUCATIONAL PSYCHOLOGY 



Bj Professor EDWARD THORHDIKE 



In this book Professor Thorndike applies to a num- 

 ber of social, and especially educational problems, the 

 methods of exact science. The topics are treated in 

 the light of the most recent researches and with the 

 aid of modern statistical technique. The book thus 

 provides those interested in education as a profession 

 or as a feature of American life with a sample of 

 scientific method in this special field as well as with 

 important information which has hitherto been inac- 

 cessible. The attitude of the author, who is the head 

 of the department of educational psychology in Teach- 

 ers College, Columbia University, and the author of 

 numerous original contributions to dynamic psychol- 

 ogy, is that of a candid and painstaking student of 

 the work that has been done in this field and upholds 

 rigorous ideals of scientific accuracy and logic. The 

 book is so written and illustrated as to be readable 

 and teachable. 



LEMCKE AND BUECHNER 



11 East 17th St., New York 



Refracting and Reflecting 



Astronomical Telescopes 



Standard and Portable 



Visual and Photographic 



OBJECTIVES 



Computed by our associate 



DR. F. R. flOULTON 



( Chicago University) 



OBSERVATORIES 



Specula, Planes, Eyepieces, etc. 



Illustration shows 5-in. with pneumatic clock. 



Photographs and Circulars on request 



LOHHANN BROS. 



GREENVILLE, OHIO : : : : U. S. A. 



