Annals of the Astrophysical Observatory of the Smithsonian Institution (1900)
Washington : Government printing office · leaf 139
ss was a scale of equal parts ruled on the ground glass base side of a long 45° prism of glass, which could be illuminated from beneath by total reflection at the hypotenuse of the prism. A cross-wire, carried by the movable frame, indicated on the illuminated scale the number of whole turns of the… … Figure 14.— Diagram of special scale for reading deflections: a, plain ground glass; 6, sliding frame; culting cork, the observer, c, cork occulter; d, cross hair; e, triangular glass scale of screw divisions; /, ground glass divided working in almost total dark¬ screw head; g, ft, lamps for…
Infrared spectra · Solar radiation
Internet Archive · Smithsonian Libraries · Public domain (published before 1931). Free to use for anything.
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