SCIENCE-ADVERTISEMENTS 



The LEITZ Travelling flicroscope II K 



with continuous side fine adjustment 



is declared the on/y reliable foldhig microseope — this due to its pre- 

 cision in mechanical workmanship, resulting in unlimited durability. 

 This feature is of special importance, considering the strenuous 

 usage a folding microscope is subjected to in field work — 



The Optics : Of the " LEITZ STANDARD "—a guaran- 

 tee in itself as being the best that optical science provides. 



Accommodated in morocco case with nickel-plated corners, it 

 measures only II J^x 8^ X 4"^ inches. 



Price: Stand with swingdown Abbe Condenser N. A. 1.20. 

 Iris below and above condenser, side screw for condenser, to raise 

 and lower same along the optical axis, Triple Nosepiece. 



Duty Paid, $82.00 Duty Free, $53.30 



Objectives and Eyepieces according to selection 



The Leitz Travelling Microscope— II K is the standard tor Beld medical work in the 

 Armies and Naviea of leading nations. For the field Biologist It Is likewiie indispensable. 



XJ. s. 

 Branch 



IV ew "V^oi'k 

 30 East IStli St. 



Science and Education 



A Series of volumes for the promotion of scienti&c research and educational progress 

 Volume I. The Foundations of Science 



By H. PoiNCARE. Containing the authorized English translation by George Bruce 

 Halsted of "Science and Hypothesis," " The Value of Science," and "Science 

 and Method. ' ' In preis. 



Volume II. Medical Research and Education 



By RicHAED Mills Peakob, William H. Welch, C. S. Minot, and other authors. 

 In press. 



Volume III. University Control. Now ready. 



Published March, 1913. Pages x+484. Price, $3.00 net 



University Control 



By J. McKeen Cattell, Professor of Psychology in Columbia University 

 Together with a Series of Two Hundred and Ninety -nine Unsigned Letters by Lead- 

 ing Men of Science holding Academic Positions and Articles by Joseph Jastrow of the 

 University of Wisconsin, George T. Ladd of Yale University, John J. Stevenson of New 

 York University, J. E. Creighton of Cornell University, J. McKeen Cattell of Columbia 

 University, George M. Stratton of the University of California, Stewart Paton of Prince- 

 ton, John Jay Chapman of New York, James P. Munroe of Boston, and Jacob Gould 

 Schurman of Cornell University. 



THE SCIEINOB PRESS 



QARRISON, N. Y. 



SUB-STATION 84, NEW YORK CITY 



LANCASTER, PA. 



