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 480
is one of the most pleasant and useful instrumentsconnected with astronomical observations. As many of these instruments are somewhatcomplicated, and very expensive, I shall directthe attention of the reader solely to one which Iconsider as the most simple—which may be pur- THE EQUATORIAL… … quadrants of 90 degrees each. There is a fixednonius at N; and the circle is capable of beingturned round on an axis. In the centre of thehorizontal circle is fixed a strong upright pillar,which supports the centre of a vertical semicircle 456 THE PRACTICAL ASTRONOMER. AB, divided into two…
Astronomy · Astronomical instruments · Telescopes
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![An illustration from Declaration de l'vsage du graphometre : par la pratique duq[ue]l l'on peut mesurer toutes distances des choses de remarque qui se pourront voir et discerner du lieu ou il sera posé : et po[ur] arpenter terres, bois, prez, & faire plans de villes et forteresses, cartes geographiques, & generalement toutes mesures visibles : et ce sans reigle d'arithmetique (1597)](https://img.insideoutlibrary.com/img/200/ia-declarationdelvs00danf-12-3.webp)
