Popular Astronomy, Volumes 56-57

achondrite American angle appear asteroid astrolabe Astronomical Society ataxites atmosphere average Bays brightness California color comet computed crater cycle December degrees diameter distance Dollond early earth eclipse Ephemeris fall February fireball galactic galaxy GEORGE VAN BIESBROECK given glass globular clusters Harvard Harvard College Observatory indicated instrument July June Jupiter latitude magnitude Mars mass maxima maximum mean measured meeting Mercury meteorite falls meteorites Meteoritical Society meteors miles month moon motion nebula Notes novae object observations Observatory OCCULTATIONS VISIBLE occur orbit paper parallax perihelion period Perseids photographic planetary planets plates POPULAR ASTRONOMY present probably radiant record region reports Saturn scientific seen shadow bands solar specimens spectra spectrum spots Stebbins stellar sunspot surface Table tektites telescope temperature theory tion University Uranus valverdites Variable Star velocity Venus VISIBLE IN LONGITUDE Yerkes Observatory