May 17, 1889.] 



SCIENCE. 



C. & C. ELECTRIC 



Electric Motors 



FOR 



Arc and Incandescent Cir- 

 cuits, Most Economi- 

 cal Motor on the 

 Market. 

 Regulation Perfect. 

 Motors Designed for all 

 Power Purposes. 



COMPANY. 



OFFICE and MANUFACTORY: 



402 and 404 Greenwich Street, New 

 York Citv. 



New England Office, 19 Pearl St,, Boston. 



Philadelpfiia Office, 301 Arcfi St. 



Western Office, 139-141 Adams Street, 

 Chicago. 



Southern Office, 25 Carondelet Street, 

 New Orleans. 



THE 



Bell Te 



COMPANY. 

 98 MILK ST., BOSTON, MASS, 



This Company owns the Letters 

 Patent granted to Alexander Gra- 

 ham Bell, March 7th, 1876, No. 

 174,465, and January 30, 1§77, 

 No. 1§6,7§7. 



The Transmission of Speech by 

 all known forms of ELECTRIC 

 SPEAKING TELEPHONES in- 

 fringes the rig-ht secured to this 

 Company by the above patents, and 

 renders each individual user of tel- 

 ephones, not furnished by it or its 

 licensees, responsible for such un- 

 lawful use, and all the conse- 

 quences thereof and liable to suit 

 therefor. 



ESTERBROOK'S 

 STEEL PENS. 



OF SUPERIOR AND STANDARD QUALITY. 

 Leading Nos.: 048, 14, 130, 135, 239, 333 



For Sale by all Stationers. 

 THE ESTERBROOK STEEL PEN CO., 



Works : Oamden, N. J. 36 John St., New VorU. 



Wants. 



A YOUNG MAN can have lucralive engage- 

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 N. D. C. HODGES, 



47 Lafayette Place, New York. 



A yr ECHANICIAN. — An optician and maker 

 ■'-'-'■ of instruments of precision of experience 

 would be glad of a position where his skill 

 would be valued in connection with some higher 

 educational institution. Address G. J., care of 

 Science, 47 Lafayette Place, New York. 



Scientific Apparattis. 



J. GRUNOW 



63J Sixtli Avenue, New York 



Established 1852. 



Microscope Stands, 

 Oil Immersion Object- 

 ives and Abbe Con- 

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 and Histological work, 

 of Objectives, Camera 

 Lucida and other ac- 

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IMPROVED OIL LIGHT 



MAGIC LANTERNS. 



Also Lime and Electric Light Apparatus, and 

 mechanical, plain, and fine colored views. 



J. B. COLT & CO., Manufacturers, 

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MAGIC Stereopticons and the Best Views 



, "V^„^,^ for Public, Church, Home, and 

 LANTERNS Scientific Exhibitions. Best appa- 

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 Years' Practical Experience, Illus, Catalogue Free. 



GEO. H. PIERCE, 

 136 S. Eleventh St., Philadelphia, Pa. 



ELECTRICAL TESTING BUREAU, 



Johns Hopkins University, Baltimore, Md. 



Resistance Coils and Boxes Compared. 



Am meters and Volt meters calibrated. 



Condensers standardized. 



Primary and Secondary Batteries Tested. 



Efficiency of Dynamos and Motors Deter- 

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Insulation of Cables and Wires Tested. 



Etc., Etc. 



Circulars describing Methods Used, Prices, 

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Address as above. 



EAELE & CO. 



SUCCESSORS TO 



B. & J. BECK, 



1016 Ciiestnut Street Phiia 



iWicroscopes and all 

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 graphic Apparatus and 

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Spectacles, Eye 

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Illustrated Price List 

 mailed free to any ad- 

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Amateur Outfits — 3- 

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 ban 40 years established in th 



E. & H. T. ANTHONY & CO. 



5gi Broaduvay, N.Y. 

 Mannfactllrers and Importers of 



PHOTOGRAPHIC INSTRUMENTS, 

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 description. Sole proprietors of 

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; line of bu 



-Mon 



GOOD NEWS 

 TO L ADIES. 



Gri.'atest nKTucement^ver of- 

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 rWi'bster's Dictionary. Forfull partlcula 



■" ■ '" ' ^- . — ™-.- . ,-,[ _ 



nrlr 



A TEMPORARY BINDER 



for Science is now ready, and will be mailed 

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47 Lafayette Place, N, Y, 



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