CHAPTER II

THE MYSTERY OF THE MILKY WAY 41

Primitive conceptions of the Milky Way. Anaxagoras and Demokritos. Ptolemaios. Galilei. Cosmogenic speculations. Wm. Herschel’s statistical researches regarding the distribution of the stars. The Milky Way as the foundation of the stellar system. The Milky Way as a nebula. Classification according to age of the stars, their distribution and velocity. Motion in the Orion nebula. The planetary nebulæ. Kapteyn’s “star-drifts.” The origin of the Milky Way. Comparison between the Milky Way and a spiral nebula in “The Dogs of Orion.” A few details from the Milky Way. The infinitely great and the infinitely small. The magnitude and destiny of the Milky Way.