The geography of the heavens : and class-book of astronomy : accompanied by a celestial atlas (1860)
Burritt, Elijah H. (Elijah Hinsdale), 1794-1838, Mattison, Hiram, 1811-1868 · New York : Mason Brothers · leaf 326
eflector is so called from M. Casse-grain, its inventor. It resembles the Gregorian, except that thespeculum placed in the focus of the reflector is convex instead ofconcave. The Herschelian Reflector differs from all others, in having nosmall reflector whatever ; the light being reflected back to… … Here the concave speculum is seen to be inclined a little to the lower side of the tube,bo that the parallel rays A are reflected back to the observer at B, at the side of theInstrument, where the eye-piece is placed. 705. Newtonian reflectors? 706. Cassegranian? Difference? Herschelian?…
Constellations · Stars
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![An illustration from Eyn schön nützlich Büchlin vnd Vnderweisung der Kunst des Messens mit dem Zirckel, Richtscheidt oder Linial : zu nutz allen Kunstliebhabern fürnemlich den Malern, Bildhawern, Goldschmiden, Seidenstikern, Steynmetzen, Scheinern auch allen Andern so sich der Kunst des Messens (Perspectiua zü latin gnant) zügebrauchen Lust haben : darin Man auch solche Kunst leichter dan ausz etzlichen hieuorgetruckten Büchern begreiffen vn lernen mag mit vil [i.e., 56] schönen darzü dienenden Figuren (1531)](https://img.insideoutlibrary.com/img/200/ia-eynschnntzlichbc00rodl-52-68.webp)
