Steel Cavalry of Modern War

Machines for War

Organization and Operation of Mechanized Forces of Our Army

Tanks, Larger Cruisers

United States Deficient in Combat Vehicles; New Type, Heavily Armed and Armored, Suggested

Achievements in Textiles

Commonplace Fabrics with Superior Chaacteristics Given by Special Treatments

Metal from the Sea

Plant Will Extract Light-Weight Industrial Metal, Magnesium, From Solution

Bond, Porcelain-Like, and more

Maestro of the Atom

Lawrence Had an Inspiration, So Science Now Has the Cyclotron for Smashing Atoms

More About the Cyclotron

For Readers Who Wish to Look Further into its Technical Details

Electron Volts, Raman Effect

So Often Seen in Print—So Seldom Interpreted; Theoretical Discovery Now Has Practical Value

An Ideal Experiment

Taking the Moon's Temperature During an Eclipse Reveals a Phenomenally Big Drop

The Temple of the Effigy

Evidences Unearthed in Ohio Afford Clear Proof of a Grisly Mound-Builder Rite

Mound Builders, Exaggerated

No Longer are They A Complete Mystery

What Makes an Aviator?

Intelligence, Adaptability, Physique, Mental and Physical Health Are Factors

50,000 Airplanes, Camera Guns, and more

How We Can Build Planes at a Rate of 20,000 a Year; Two Types Permit Economical Aerial Gunnery Practice; Pick Up Aircraft After Crashes or Forced Landings

Bleeders, Theelin, and more

Is your Pet Dentifrice Safe?

Most Dentifrices Are Good but Many of the Claims Made Are Not Justified

Why Universal Fingerprinting?

Desirable Features of System Far Outweigh Erroneously Imagined Criminal Aspects

Healthier Plants, Heroic Casting, and more

Fifth Annual Scientific American Amateur Photography Contest