The geography of the heavens and classbook of astronomy; (1863)
Burritt, Elijah H. (Elijah Hinsdale), 1794-1838, Mattison, Hiram, 1811-1868, Whitall, Henry, 1819-1887? Celestial planisphere. [from old catalog] · New York, Mason brothers; Boston, Mason & Hamlin; [etc., etc.] · leaf 252
and their orbits are not confined to any par-ticular part of the heavens ; nor do they observe any one generaldirection. The orbits of the planets approach nearly to circles, whilethose of the comets are very elongated ellipses. A wire hoop,for example, will represent the orbit of a planet. If two… … Here it will be seen that the orbit is very eccentric, that the perihelion point is verynear the Sun, and the aphelion point very remote. There is, however, a practical difficulty of a peculiar nature which embarrasses thesolution of the question as to the form of the cometary orbits. It so happens…
Constellations · Stars
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