Popular astronomy : a concise elementary treatise on the sun, planets, satellites and comets (1865)
Mitchel, O. M. (Ormsby MacKnight), 1809-1862 · New York : Oakley & Mason · leaf 23
sphere of the heavens once a year, with uniformvolocity, in a circular orbit, of which the earth was in thecenter. This hypothesis accounted fully for all the discoveredphenomena, and justly ranks among the most importantof the primitive discoveries. The gnomon gave to the old astronomers a… … Let AB represent the gnomon, ^ the shadow of thevertex at noon on the day of the summer solstice, andA^ the shadow at noon on the day of the winter solstice.Then will the angle AA A measure the entire motionof the sun from north to south ; and as one half of thismotion lies north and the other half…
Astronomy
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