The Psycholoǵy of Liǵht.—I

The Subjective Aspect of Optics

Tar as a Fuel for Diesel Enǵines

Modern Methods of Bunkering Steamers

How Speed and Cleanliness are Secured

Fireless Locomotives

Using Superheated Water in Place of a Coal Fire

Some Facts about Malaria

Its Cause and Mode of Propagation

Return Fliǵht of Carrier Piǵeons

Novel Theory Advanced—Hints for Aviators

Insect Aviation

Nature as an Aeronautical Engineer

A Great Modern Telescope

The Sixty-inch Reflector of the Mount Wilson Observatory

Insurance aǵainst Unemployment in France

Government Aid for the Man Out-of-WorK

The Stability of Aeroplanes

An Investigation of the Air Pressure on Aeroplane Surfaces

Distribution of Germs in the Air

Electric Waves Directed by Wires

Their Use in Multiplex Telephony and Telegraphy

The Senses of Plants

Their Reaction to Various Stimuli

The World's Production of Aluminium

Gas Enǵineerinǵ and Refriǵeration at the Massachusetts Institute of Technoloǵy

Trade Notes and Formulæ

Municipal Efficiency Bureau

Science Notes