



Produced by J. Niehof, D. Kretz, J. Sutherland, and
Distributed Proofreaders











[Illustration]




SCIENTIFIC AMERICAN SUPPLEMENT NO. 433




NEW YORK, APRIL 19, 1884

Scientific American Supplement. Vol. XVII, No. 433.

Scientific American established 1845

Scientific American Supplement, $5 a year.

Scientific American and Supplement, $7 a year.


       *       *       *       *       *

TABLE OF CONTENTS.

I.    CHEMISTRY, METALLURGY, ETC.--New Analogy between
      Solids, Liquids, and Gases.

      Hydrogen Amalgam.

      Treatment of Ores by Electrolysis.--By M. KILIANI.

II.   ENGINEERING, AND MECHANICS.--Electric Railway at Vienna.--With
      engraving.

      Instruction in Mechanical Engineering.--Technical and trade
      education.--A course of study sketched out.--By Prof. R.H.
      THURSTON.

      Improved Double Boiler.--3 figures.

      The Gardner Machine Gun.--With three engravings showing the
      single barrel, two barrel, and five barrel guns.

      Climbing Tricycles.

      Submarine Explorations.--Voyage of the Talisman.--The Thibaudier
      sounding apparatus.--With map, diagrams, and engravings.

      Jamieson's Cable Grapnel.--With engraving.

      A Threaded Set Collar.

III.  TECHNOLOGY.--Wretched Boiler Making.

      Pneumatic Malting.--With full description of the most improved
      methods and apparatus.--Numerous figures.

      Reducing and Enlarging Plaster Casts.

      Stripping the Film from Gelatine Negatives.

IV.   ELECTRICITY.--Non-sparking Key.

      New Instruments for Measuring Electric Currents and Electromotive
      Force.--By MESSRS. K