A Laboratory "Thundercloud" to Aid Aviators

'Maid-Of-All-Work'

Place of the Versatile Destroyer in Modern Navies

Inch by Inch, Tooth by Gear

Army Officers Receive Technical Training in Motor Vehicle Operation and Up-Keep

Smokeless Powder

Chopped-Up Cotton Speeds Production

Shutters and Cutters

High-Speed Motion-Picture Photography Used in Study of Machine-Tool Cutting Edges

Glass Blocks Bend Light

Daylight Conservation Achieved by Refraction of Incoming Light to Ceilings and Sidewalls

Safe at Work, Light, and more

Better Lighting Reduces Industrial Hazards

Stellar Advertising Signs

Neon, So Rare on Earth, Proves to be 1000 Times More Abundant in the Stars

Ancient Ostia

Ignoring Present-Day Strifes, Archeologists Unearth Rome's Once-Thriving Seaport

Fossil

World's Oldest Evidence Of Animal Life

No Mystery In Pep

Seven Simple Rules for Getting and Maintaining a Reserve of Vigor

Yardstick, Noise

For Planning the Daily Diet; Ear Plugs Protect Industrial Workers

For Better Paint

Methods of Testing Surface Coatings for Metals Have Definite Place in Maintenance

Cloud Charge, Canal Lighting, and more

Mobile Power, Coach-Sleeper, and more

Railway-Car Plants For U. S. Navy

Glue Spreader, Hand Guards, and more

Military Rockets

Anti-Aircraft Traps, Rocket Shells, Weather Study, Airplane Starters, are Possibilities

Flying Boat, Skyfarer, and more

Could Fly Non-Stop to Europe and Return

Winning Pictures in Scientific American's 6th Annual Photography Contest