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Diffraction Grating
From the collection of National Museum of American History. Free to download, adapt and use — no permission needed.
About this work
Henry A. Rowland, a professor of physics at The Johns Hopkins University, designed an engine that produced diffraction gratings by ruling a large number of closely spaced lines on a metal surface. The concave speculum metal mirrors for many of these gratings were ground and polished in John A. Brashear's shop in Pittsburgh. The mirrors were sent to Baltimore, where Theodore C. Schneider ruled them with Rowland's engine, and then returned to Pittsburgh for sale to scientists around the world.
National Museum of American History’s own descriptionSubjects
Credit lineDiffraction Grating. 1884. Rowland, Henry A.. National Museum of American History, U.S. Military Academy. CC0.
