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Near-Vacuum Chamber Tests Supersonic Propellers

Fluoridation Cuts Caries

Most Delicate Flint Work

Extreme Cold Key to What Makes Steel Really Hard

Books of the Week

New Machines and Gadgets

Ozone as Preservative

Replacement of Teeth

[Photograph]: Maps Needed

Warmer and Drier November for U. S.

Search for Scientists

Ills Show in Fingerprints