Feature

Weather Cycles Make Possible 25-Year Rainfall Predictions

Movies of Sunset on Moon Are Shown before Scientists

Age of Prehistoric Man Measured by Elephant Teeth

Frequent Revolutions Chief Cause of Poor Health

Dust, Soot, Smoke and Fumes: “A Classic Invention”

New Sand Trap Cleans Irrigation Water

First Glances at New Books

Yellowstone Geyser Water Would Make Only Small River

Atoms Combine in Sun’s Atmosphere

Front Matter

Carbonic Acid in Air Keeps Earth Warm

Rare Element Gives New Kind of Light