Handbook of Astronomy

altitude annual motion aphelion apparent diameter apparent magnitude apparent motion ascertained astronomical atmosphere attraction axis bodies C. H. F. Peters called celestial equator celestial pole celestial sphere centre change of position circle comet degree density determined direction disk disturbing diurnal motion earth ecliptic effect elongation equal equatorial equinoxial points excentricity explained firmament fixed globe gravity greater heavens hemisphere Herschel horizon increase inferior conjunction inferior planet instrument interval Jupiter latitude length less light line of collimation longitude lunar mass mean distance measured meridian miles moon moon's move nearly nebula night object Observatory observed orbit parallax parallel pendulum perihelion period phenomena planet Plate pole prime vertical produced refraction represented revolution revolve right angles right ascension ring rotation round the sun satellites Saturn seen sidereal solar system sphere spots stars sun's supposed surface telescope terrestrial tion transit Uranus velocity visible visual wires