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SCIENCE 



[fKW Series. TTdttiav- Mav Id. 1 SQ7 Single Copies, 15 ors. 



Vol. V. No. 124. r iilUA.\ , iVXAl i.'±, LOV i . ANNUAL SOBSCEIPTION, S6.00. 



OF 



QUEEN & CO., Inc., 



Was Established in 1853 and Reorganized in 1896, and consists of the following Sales Departments : 

 Optical Department, comprising Optical and Ophthalmological Instruments, and Field and Opera Glasses. 



Mathematical and Engineering Department, comprising Drawing instruments and Materials and 



Engineering and Surveying Instruments. 

 Microscopical Department, comprising Microscopes, Magnifiers, and Botanical and Bacteriological Supplies. 



Physical and Electrical Depairtment, comprising Physical and Electrical Instruments and Apparatus, 

 X-Kay Apparatus and Anatomical Models. 



Astronomical and Projection Department, comprising Projection Lanterns, Astronomical Telescopes, 

 and Polarizing Apparatus. 



Meteorological Department, comprising Meteorological Instruments, Barometers, and Thermometers, and 



Pyrometers for physical and technical use. 

 Photographic Department, comprising Cameras and Lenses and Photographic Supplies in general. 

 Chemical Department, comprising Chemicals and Chemical Apparatus and Fine Balances. 



These Sales Departments depend principally upon onr WELL EQUIPPED FACTORIES, of which we 

 maintain the following : 



Physical, Electrical and Engineering Instrument Factory, 



Optical Factory, Thermometer and Chemical Glassware Factory, 



Electrical Laboratory, Wood Working Factory. 



Each of our Sales and Manufacturing Departments is under a competent manager, with whom is associated 

 an able corps of assistants, many of whom are recognized experts in their special lines. 



In addition to our own products, we represent a number of well-known Foreign Houses about whose appara- 

 tus, which we Jean supply either from stock or import Duty Free for institutions, we are at all times prepared 

 to give information. 



Catalogues and Circulars of any of the Departments will be sent free by mail on application. 



QUEEN & CO., INC., 



N. Y. Office: 116 Fulton St. 1010 Chestnut Street, Philadelphia. 



