Baly, E. C. C. (Edward Charles Cyril), b. 1871 · London, Longmans, Green · leaf 229
the lower end of C is a pin, P, on which is fitted a secondbrass plate, D, which thus can revolve on the axis P. Thismotion is controlled by the screw S, and a spring which is notshown in the diagram. The grating itself stands on two pro-jections from the bottom of D, and is held up against D…
Spectrum analysis
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