Feature

Twin-Training Experiments May Be Great Historic Event

Strong Fortress of Incas Unearthed in Peru

Nature Ramblings: Maldistribution of Water

Accidents Killed 99,000 Persons during 1934

First Glances at New Books

Front Matter

Long-Distance Plane Flights Will Go to High Altitudes

[Photograph]: Great Altar

Six Hundred Billion Volt Cosmic Rays Predicted

U. S. Largely Unmapped; Completion of Work Urged

Spores of Fungi Captured in Arctic Upper Air

Sleeps Three Days at Time; Woman Puzzles Doctors