Mining Gold by Proxy

The Old-Fashioned Miner Replaced by Machinery

Report on the Condition of Aeronautics in Germany

Extracts from a Report by the American Consul-General, Berlin, April 4th, 1913

The Increased Cost of Warships

Floral Blue

Human and other Population of the United States

Pork Production

The Pendulum Propeller Rudder

An Oscillating Substitute for the Screw

High-Frequency Generator

For Wireless Telegraphy and Telephony

Classification of Igneous Rocks

Rat-proof Buildings

The Lava Fountains of Kilauea

Observations by Telephotography

Propagation of High-Frequency Electric Waves along Wires—II

Advantages and Limitations of the System for Practical Operation

A Convenient Method for Drawing Five- Centered Arches

Mind and Matter