ABSTRACT
Mizar is a spectroscopic binary, and also a visual binary; Alcor, the rider, moves with it, and so apparently do all but the outermost two of the seven stars in the 'Plough'. Other systems are equally distinct, the famous Pleiades, for instance, and, judging from their similarity of spectra, most of the bright stars in Orion. The visible universe is almost symmetrically divided by the Milky Way, where Helium and gaseous stars and nebule do congregate, while other nebule are rare, so that it may easily be regarded as the fundamental plane of the universe. Newcomb proposes a reference to the astrographic survey when completed, to decide this question. Easton, following out Keeler's pregnant suggestion, sees in its rifts and other irregularities evidence of spiral structure in the galaxy itself, with the solar system eccentrically placed between two successive wisps.
