A high-school astronomy: in which the descriptive, physical, and practical are combined .. (1859)
Mattison, Hiram, 1811-1868 · New York, Mason brothers · leaf 127
? Great-est diameter at the earths surface ? Of penumbra ? 256. What is an appulse ? A partial eclipse ? A total? A central? Areall central eclipses total? Why not? What called then ? Why ? 257. Why are some central eclipses total, and others partial and annular?(Diagram.) 6 122 ASTRONOMY. follows… … 1. At A, the earth is at her aphelion, and the sun being at his most distant point, willhave his least apparent magnitude. At the same time, the moon is in perigee, and ap-pears larger than usual. If, therefore, she pass centrally over the suns disk, the eclipsewill be total. 2. At B, this order is…
Astronomy
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