Signedunsigned
InscribedStamped: HCO / 1701
FunctionThis form of diffraction grating would be put on the end of telescope tube and produce a spectrograph of whatever was observed with the telescope.
The distance between the wires (about 1.5 lines per mm) suggests it was used for microwave or infrared radiation.
Historical AttributesUsed by Harvard College Observatory at its Oak Ridge Station.
ProvenanceHarvard College Observatory, Oak Ridge Station; transfer to CHSI in 2005.
Related WorksGeorge Sweetnam, "Diffraction grating and ruling engine," in Instruments of Science, ed. Robert Bud and Debroah Jean Warner (New York, 1998), 171-173.