| TABLE OF CONTENTS. |
|---|
| I. | [CHEMISTRY AND METALLURGY.—The Determinationof Graphite in Minerals.—By J.B. MACKINTOSH.] |
| [Sulphocyanide of Potassium.] |
| [Sugar Nitro-glycerine.] |
| [On Remelting of Cast Iron.] |
| [The Hardness of Metals.] |
| II. | [ENGINEERING, ETC.—The Jet Ventilator. 4figures.] |
| [Feeding Boilers at the Bottom. 2 figures.] |
| [The Honigmann Fireless Engine.—The firelessworking of steam engines by means of a solution of hydrate ofsoda.—With several figures and diagrams.] |
| [Simple Methods of Calculating Stress inGirders.—By CH. LEAN.—With full page ofillustrations.] |
| [A Spring Motor.] |
| [Steam Yachts.] |
| III. | [TECHNOLOGY.—Foucault's Apparatus forManufacturing Illuminating Gas and Hydrogen. 2 figures.] |
| [The Circle Divider.] |
| [Soluble Glass.—Process ofmanufacture.—Use.] |
| [Iron Printing and MicroscopicPhotography.—Formulas for printing solutions.—Compoundnegatives.] |
| [Practical Directions for Making LanternTransparencies.—By T.N. ARMSTRONG.] |
| [Casting Chilled Car Wheels. 6 figures.] |
| IV. | [ELECTRICITY, ETC.—Electricity andPrestidigitation. 2 figures.] |
| [Portable Electric Safety Lamp. 6 figures.] |
| [The Electric Discharge and Spark PhotographedDirectly without an Objective. 6 engravings.] |
| V. | [PHYSICS, ETC.—The True Constant ofGravity.] |
| [Origin of Thunder Storms.] |
| [Physics without Apparatus.—Manufacture ofilluminating gas.—Elasticity of bodies. 2 figures.] |
| [Scientific Amusements.—Dance of electrifiedpuppets.—Silhouette portraits. 2 figures.] |
| [A Sunshine Recorder. 2 figures.] |
| VI. | [MEDICINE, HYGIENE, ETC.—How Cholera isSpread.] |
| [Sulphurous Acid and Sulphide of Carbon asDisinfecting Agents.—Methods of burning the same.] |
| VII. | [MISCELLANEOUS.—Improvised Toys.—Withnumerous illustrations.] |
| [The Æolian Harp.—Kircher's harp, madein 1558.—Frost and Kastner's harp.—Manner of making theharps. 4 figures.] |
| [How to Break a Cord with the Hands. 1 figure.] |
| [An Aquatic Velocipede for Duck Hunting. 2engravings.] |
| [Skeleton of a Bear Found in a Cave in Styria,Austria.] |
| VIII. | [BIOGRAPHY.—Theodor Billroth, Prof, ofSurgery at Vienna.—With portrait.] |
