A high-school astronomy: in which the descriptive, physical, and practical are combined .. (1859)
Mattison, Hiram, 1811-1868 · New York, Mason brothers · leaf 126
at one of her nodes. If lunar, it istotal, as the earths umbra is always broad enough, atthe moons distance, if centrally passed, to obscure herwhole disk. But a solar eclipse may be central and nottotal, as the moon is not always of sufficient apparentdiameter to cover the whole disk of the sun*… … 257. It has already been shown (56) that the apparentmagnitudes of bodies vary as their distances vary ; andas both the earth and moon revolve in elliptical orbits, it 255. Average length of the moons umbra ? Does it vary ? Why ? Great-est diameter at the earths surface ? Of penumbra ? 256. What is…
Astronomy
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