Reaping the Whirlwind, The Natural Time Unit in the Organic World and more

How Mexican Rebels Destroy Railways and Bridges

The Military Value of Low Flying, The Two-speed Rear Axle and more

Opening of the World's Greatest Power Plant

Damming the Mississippi River to Produce 300,000 Hydro-electric Horse-power.

An Encyclopaedia on the Card-index System, Military Aviation in Italy and more

By Our Berlin Correspondent

The Current Supplement - September 13, 1913

The Industrial Need of Technically Trained Men.--VII

The Possibilities That Await the Hydraulic Engineer