Feature

Two-Purpose Machine Gun Mount Is Recent Patent

Wild Geese, Prized in U. S., Are Pests on Far South Isle

Half of Railroad Trackage Still Lacks Block Signals

Nature Ramblings: The Tale of Teeth

Indians of Both Americas Targets of “Fifth Columns”

First Glances at New Books

Front Matter

Star Study Program Will Not Be Finished Until 2019

Ancient Gateway of Kish Reconstructed in Museum

Rocket Journey to Moon Shown at Fels Planetarium

Navy’s Chronometer Shortage Not Serious; Radio Helps

Technical School Merger Announced in Chicago