Jf///^ 



SCIENCE 



New Series. 

 Vol. VII. No. 179. 



Friday, June 3, 1898. 



HiNGLE Copies, 15 cts. 

 Anndal Subscription, $.5.00 



General Electric Co.'s 



FLUOROSCOPES 



Platino-cyanide of Barium, or Tungstate of Calcium Screens. 



NEW X=RAY TUBE 



EFFICIENT. 



WITH AUTOMATIC 



VACUUM REGULATOR. 



LONG-LIVED. 



ROENTGEN RAY APPARATUS of all kinds. 



Catalogue No. 9050. 



Candelabra, Miniature and Decorative Lamps. 



Catalogue No. 9044. 



Eflison Decorative and miniature lainn Depatttneat, 



(GENERAL ELECTRIC COMPANY,) 



HARRISON. N. J. 



Minerals. 



Agates, polished, 1.5 to 60c. ; Malachite, polished, 20c. to $1. 

 Labradoi-ite, polished, 25 to 7oc. Cut Stones suitable for mount- 

 ing. Garnets, deep ruby red color, SI to S2. Moonstones, 50c. to 

 ifl.50. Sapphire (blue), SI to $5. Turquols, 2.5c. to $2. Varlsclte, 

 7 iC. to fl. Opals, 50c. to S3. Moss Agate, 35c. to $1. ChrysKprase, 75c. to S1.25. Amethyst, 3bc. 

 t' J S2. Aquamarine, 35c. to S2. Citrine, $1 to S3. .50. Crocidolite, S35c. to 50c. Our stock of Min- 

 erals both massive and crystallized for either cabinet or museum purposes is unequalled. Write for 

 iitiything you may need in the mineral line, and we will promptly quote you prices and full particu- 

 lars. Send lor Circulars. Mineral Catalogue, 159 pages, 20c. 



WARD'S NATURAL SCIENCE ESTABLISHMENT, 18-28 College Ave.. Rochester. N.Y. 



iwuja.3Fi.ij-sr HE.iSk.DTe- 



? W^ 



it; 



f/ 



Electric Furnaces, Generators and Burners 



CONTENTS : Introduction — Acetylene — Dangers of Acetylene : Explosiveness, Acetylide of Copper, 

 Toxic Properties, Effects on the Eye3=EIectric Furnaces : Intermittent Furnaces, Continuous Furnaces — 

 Generation of Acetylene — Impurities of Carbide and Purification of Acetylene — Generators — Acetylene 

 Lamps — Acetylene Burners — Author's Experiments— Conclusion — Fire Eegulations — List of U. S. Patents. 



12II10. Clotb. Illustrated. Price, $1.50 



0. VAN NOSTRAND COMPANY, Publisher, 23 Murray and 27 Warren Sts., New York 



%* Copies sent by mail and express on receipt of price. 



