The practical astronomer : comprising illustrations of light and colours, practical descriptions of all kinds of telescopes, the use of the equatorial-transit, circular, and other astronomical instruments, a particular account of the Earl of Rosse's large telescopes, and other topics connected with astronomy (1845)
Dick, Thomas, 1774-1857 · London : Seeley, Burnside, and Seeley · leaf 518
y a levelinstead of a telescope, and sometimes by a plumb-line G, suspended from near the centre, andbrought to bisect a fine dot made on the limb,where a microscope is placed to examine the bisec-tion. The weight or plummet at the end of theplumb-line is suspended in the cistern of water6, which… … at right angles to the telescope, when it is placedat o. The quadrant is screwed by the centre ofits frame, against a piece of brass e with threescrews, and this piece is screwed to the top of thepillar B with other three screws. By means ofthe first three screws, the plane of the quadrantcan be…
Astronomy · Astronomical instruments · Telescopes
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