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Common terms and phrases
61 Cygni aberration of light accurate actually angle angular distance annual motion apparent diurnal motion apparent motion astronomical attraction axis of collimation binary star called celestial sphere centre circular colatitude consequently consider constellation culmination declination describe determined diameter direction diurnal motion divisions double star Dunsink earth ecliptic ellipse equal equator exceedingly explain fixed stars follows globe graduated circle Greenwich heavens hemisphere hence horizon interval Jupiter Kepler's kilometres known latitude length magnitude mean noon mean solar mean sun measure Mercury meridian circle minute moon nearly nebulæ objects observations orbit parallel passes pegtop perpendicular pivots planet Pleiades polar axis polar distance Pole Star proper motion protractor radius rays refraction remarkable revolution right ascension rotation round the sun satellites seen sidereal clock sidereal day Sirius subtends sun's suppose supposition surface tance tele tion transit instrument unaided eye Venus vernal equinox visible wire zenith distance
Popular passages
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Page 96 - since the angle between two planes is equal to the angle between the perpendiculars to those planes drawn through a point