[Republican soldiers carrying field telephone equipment, Rio Segre, Aragon Front, near Fraga, Spain]

[Signal Corps sets up its radio equipment in the scenic surroundings near atomic bomb test]

[Group of men crowd around a man operating and demonstrating radiation testing equipment, Yucca Flat, Nevada]

[Group of men crowd around a man operating and demonstrating radiation testing equipment, Yucca Flat, Nevada]

[Group of men crowding around a man operating and demonstrating radiation testing equipment, Yucca Flat, Nevada]

[Group of men crowded around a van looking in at a man operating radiation test equipment, Yucca Flat, Nevada]