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1940 s

40 s

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auto manufacturers check

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Civilian defense. War Emergency Radio Service. These three War Emergency Radio Service transmitter-receivers tuned to different wave lengths keep this Civilian Defense control center in touch with three different channels of communication. The set being operated maintains contact with state and city police and fire departments. The other two are used for communicating with sub-control centers, hospitals, and mobile field units

Civilian defense. War Emergency Radio Service. These three War Emergen...

Public domain photograph of indoor, interior activity, America in the 1930s, free to use, no copyright restrictions image - Picryl description

Machine performs half a day's manual labor in 5 minutes. Washington, D.C., Dec. 22. H.J. Keegan of the U.S. Bureau of Standards, using the spectrophotometer to determine the different colors in a piece of cloth. It formerly took a man a half a day to make this spectrum analysis but now the machine does it in five minutes. The machine measures the % of light transmitted or reflected at various wave lengths in the visible spectrum

Machine performs half a day's manual labor in 5 minutes. Washington, D...

Picryl description: Public domain image of a bureau, office furniture, desk, chair, free to use, no copyright restrictions.

Interferometer tests standard gages for automobile manufacturers. Washington, D.C. May 28. I.J. Fullmer of the Bureau of Standards is shown with an interferometer by means of which differences in length are measured in terms of wave-lengths of light to the millionth of an inch. A four-inch square precision gage is being compared for length with the Bureau's standard 4 inch, which is rectangular in shape. These gages are tested against the master gages which the different auto manufacturers check their measuring devices so that the parts of the cars separately made can be, when assembled, fitted perfectly. The standard gage and the master gage are shwon being compared in the interferometer, 5/28/37

Interferometer tests standard gages for automobile manufacturers. Wash...

Public domain photograph of laboratory, scientist, free to use, no copyright restrictions image - Picryl description