Modern Ideas on the End of the World

New Contributions to Cosmology Obtained from the Development of Differential Theories

The Conditions of Industrial Accidents

Gardens of the Zoological Society of London

Its History, Organization, and its Valuable Collections

Efficiency of Coal and Electric Heaters

A New Era in the Science of Nutrition

How Two Masters in the Art of Experimentation are Bringing this About

Recent Developments in X-Ray Tubes

A Novel Engineering Expedient

The Cutlery Works of Thiers

Manufactures of the Old French Town where Knives have been Made for Centuries

Old English Seals

The Reaction of the Planets upon the Sun—I

Influence of the Earth and a Study of Sun Spots

Selenium Cell Making

Gyrostatic Action—II

As Applied to Torpedoes, Submarine Craft and Aeroplanes

Gasoline from “Synthetic” Crude Oil

Some Remarkable Experiments with Oils and Method of Obtaining an Additional Yield of Gasoline

Hydrogen and the Rare Gases

Electrical Conductivity Imparted to Liquid Air by Alpha Rays