Cutting screen door stock to measurement. This material is known as 5/...
Public domain photograph of Louisiana in 1930s, free to use, no copyright restrictions image - Picryl description
Measuring a standard last to see how it conforms to individual measure...
Public domain photograph of 1930s industry, war production in the United States free to use, no copyright restrictions image - Picryl description
Cutting screen door stock to measurement. Screening demonstration. Sai...
Picryl description: Public domain image of workers, labor, 1940s, economic conditions, free to use, no copyright restrictions.
![New fathometer used at full speed. Washington, D.C., May 7. Dr. Herbert Grove Dorsey of the U.S. Coast and Geodetic Survey has invented an instrument to secure the precise measurement. The machine sends a sound, pitched so high that it is above audibility, traveling thru the water a known speed, the sound hits the bottom and returns as an echo at 20 times per second. The fathometer is so accurate that a change in depth of three inches can be detected. the indications are made by a flash from a neon tube, viewed thru a rotating disc, the flash of light appearing to stand still and the depth is read as easily as a clock. The instrument indicator is installed in the pilot house (at the top of the machine) and the transceiver (the disc at the right of the machine [?]) is located in the hull of the ship, 5/7/1937](https://cache.getarchive.net/Prod/thumb/cdn4/L3Bob3RvLzE5MzcvMDEvMDEvbmV3LWZhdGhvbWV0ZXItdXNlZC1hdC1mdWxsLXNwZWVkLXdhc2hpbmd0b24tZGMtbWF5LTctZHItaGVyYmVydC1ncm92ZS1kb3JzZXktMTAyNC5qcGc%3D/40/50/webp "New fathometer used at full speed. Washington, D.C., May 7. Dr. Herbert Grove Dorsey of the U.S. Coast and Geodetic Survey has invented an instrument to secure the precise measurement. The machine sends a sound, pitched so high that it is above audibility, traveling thru the water a known speed, the sound hits the bottom and returns as an echo at 20 times per second. The fathometer is so accurate that a change in depth of three inches can be detected. the indications are made by a flash from a neon tube, viewed thru a rotating disc, the flash of light appearing to stand still and the depth is read as easily as a clock. The instrument indicator is installed in the pilot house (at the top of the machine) and the transceiver (the disc at the right of the machine [?]) is located in the hull of the ship, 5/7/1937")
New fathometer used at full speed. Washington, D.C., May 7. Dr. Herber...
Public domain photograph of people in office, interior, the 1910s-1920s America, free to use, no copyright restrictions image - Picryl description
Cutting screen door stock to measurement. Saint Mary's County, Ridge, ...
Picryl description: Public domain image of a construction site, wooden frame, timber, free to use, no copyright restrictions.
Conversion. Farm implements to cargo winches. Making a vernier caliper...
Public domain photograph - working class people, the 1930s United States, work, labor, worker, free to use, no copyright restrictions image - Picryl description
Barometrical measurement of the Blue-Ridge, Warm Spring, and Alleghany...
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Dr. Eleanor Hunt. Dr. Hunt measuring width of boy below buttocks II
Public domain photograph of midcentury American portrait, 1940s-1950s, free to use, no copyright restrictions image - Picryl description
Measurement instrument, National Academy of Sciences, Washington, D.C.
Digital image produced by Carol M. Highsmith to represent her original film transparency; some details may differ between the film and the digital images. Title, date, and keywords provided by the photographer.... More
Barometrical measurement of the Blue-Ridge, Warm Spring, and Alleghany...
Picryl description: Public domain document page scan, free to use, no copyright restrictions image.
Barometrical measurement of the Blue-Ridge, Warm Spring, and Alleghany...
Picryl description: Public domain document page scan, free to use, no copyright restrictions image.
Barometrical measurement of the Blue-Ridge, Warm Spring, and Alleghany...
Picryl description: Public domain document page scan, free to use, no copyright restrictions image.
Cutting screen door stock to measurement. Screening demonstration. Cha...
Picryl description: Public domain image of a worker, labor, factory, plant, manufacture, industrial facility, 1930s, mid-20th-century industrial photo, free to use, no copyright restrictions.
Map of the town of Morrisania - Public domain old map
Survey map showing block dimensions, street dimensions, street grades, and angle of street intersections. Does not show cadastral data. Relief shown by spot heights. "Made by and under the direction of the unde... More
Barometrical measurement of the Blue-Ridge, Warm Spring, and Alleghany...
Picryl description: Public domain document page scan, free to use, no copyright restrictions image.
Cutting screen door stock to measurement. Screening demonstration. Sai...
Picryl description: Public domain photograph of a worker, construction, carpenter, 1930s, free to use, no copyright restrictions.
Barometrical measurement of the Blue-Ridge, Warm Spring, and Alleghany...
Picryl description: Public domain document page scan, free to use, no copyright restrictions image.
Barometrical measurement of the Blue-Ridge, Warm Spring, and Alleghany...
Picryl description: Public domain document page scan, free to use, no copyright restrictions image.
Barometrical measurement of the Blue-Ridge, Warm Spring, and Alleghany...
Picryl description: Public domain document page scan, free to use, no copyright restrictions image.
Uncle Sam's color expert. Washington, D.C., Sept. 20. Miss Dorothy Nic...
A woman sitting at a desk in front of a typewriter. Public domain portrait photograph, free to use, no copyright restrictions image - Picryl description
Barometrical measurement of the Blue-Ridge, Warm Spring, and Alleghany...
Picryl description: Public domain document page scan, free to use, no copyright restrictions image.
Barometrical measurement of the Blue-Ridge, Warm Spring, and Alleghany...
Picryl description: Public domain document page scan, free to use, no copyright restrictions image.