首页 / 官方藏书 / On the Construction of a Silvered Glass Telescope / Fifteen and a half inches in aperture, and its use in celestial photography / §3. THE CLOCK MOVEMENT.
首页 / 官方藏书 / On the Construction of a Silvered Glass Telescope / Fifteen and a half inches in aperture, and its use in celestial photography / §3. THE CLOCK MOVEMENT.