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 161
is the following. Let two circles be drawnon a smooth round board, covered with whitepaper, as in fig. 34: Let the outermost be dividedinto 360 equal parts; then draw seven right linesas A,B,C, &c, from the center to the outermostcircle, making the lines A and B include 80degrees of that… … D ing to orange near G; GF orange, inclining toyellow near F ; FE yellow, inclining to green nearE; ED green, inclining to blue near D; DC blue,inclining to indigo near C ; CB indigo, incliningto violet near B ; and BA violet, inclining to asoft red near A. This done, paint all that partof the…
Astronomy · Astronomical instruments · Telescopes
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