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 347
r a support to the eye-piece, andfor directing the motion of the instrument. Atelescope of 40 or 50 feet in length, constructedon this plan, would not require one fifth of theexpense, nor one fourth of the apparatus andmechanical power for moving it to any requiredposition, which were found… … fig. 71, where A is the short tube, BC and DEthe two large bars or arms, connected with crossbars, for the purpose of securing strength andsteadiness. At I and K, behind the speculum,weights might be applied, if necessary, for coun-terbalancing the lever power of the long arm. Frepresents the…
Astronomy · Astronomical instruments · Telescopes
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