Popular Science Monthly, v. 135, n. 1, 1939

Google Books

135

1939-07

Public domain (Google digitized)

Is Part Of
Title	Alternate label	Class
British gunners trained using a model plane on a stick
Balloons used as rescue markers to aid locating airplane pilots
Maps in relief made by a new device
British mobile first-aid station built into bus
Photos taken by a truck with a tall ladder
Aerial mine fields planted with balloons
Planes built with flush rivets could get more speed
New radio system designed to prevent airplane collisions
New airplane motor designed without pistons
New British method for teaching sailors to swim