In these days when space travel is taken for granted, and digital images from a colossal orbiting telescope are commonplace, and an astronomer’s official title is “astrophysicist,” when the means and the tools of the old astronomy and the old astronomers have been relegated to museum cases, it is apropos — in this fiftieth anniversary of man’s alighting on the moon — to take a look backward to the days when astronomers were priests, and astronomy was both a royal and a sacred science. Men in those days saw the sky differently — and understood it differently. Their heavens were enclosed within the visible celestial sphere, and the mechanics of the heavens were understood using such tools as the armillary sphere. Even today, the armillary sphere has something to teach modern sky-watchers about the motions of the heavens, about the constellations and planets, and about a conception of the heavens which we have all but lost.