The Great 36-inch Refractor of the Lick Observatory, ca. 1888

This early picture of the Lick 36-inch refractor—then the world's most powerful telescope—shows the eyepiece end, at which is mounted an instrument for visual measurement of star positions. The "ship's wheels" were used by the observer to control the motion of the telescope; the two smaller telescopes mounted atop the main tube are finder scopes for locating targets.