Feature

Cause of Night Glow of Sky Is Magnetic Activity

First Glances at New Books

Crocodile Stomach Stones Travel Safely through War

Nature Ramblings: Inches of Rain

X-Rays with Microscope Reveal Hidden Flaws in Metals

First Glances at New Books

Front Matter

Expect Victory or Disaster in War on Sleeping Sickness

[Photograph]: Medium

Two New Methods of Gaging Altitude of Airplanes

[Photographs]: Ordinary Photograph

Mystery Explosive Plant May Be Effort to Avoid Bottleneck