Lockyer, Norman, Sir, 1836-1920, Seabroke, G. M. (George Mitchell), 1848-1918 · London, Macmillan and co. · leaf 348
description of the transit circle we saw how theAstronomer-Royal had contrived to throw light into theaxis of the telescope, so that the wires were cither ren-dered visible in a bright field, or, the field being keptdark, the wires were visible as bright lines in a dark field.That is the difterence… … Fig. 149.— Illuminating lamp for equatoiial. of the telescope. Near the eyepiece is a small lamp, d,swung on pins on either side which rest on a circular pieceof brass swinging on a pin at c, and a short piece oftube at E, through which the light passes into the tele-scope and falls on a small…
Astronomy · Telescopes
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