首页 / 官方藏书 / The Modern Clock / A Study of Time Keeping Mechanism; Its Construction, Regulation and Repair / CHAPTER XIX. THE CONSTRUCTION OF SIMPLE AND PERPETUAL CALENDARS.
首页 / 官方藏书 / The Modern Clock / A Study of Time Keeping Mechanism; Its Construction, Regulation and Repair / CHAPTER XIX. THE CONSTRUCTION OF SIMPLE AND PERPETUAL CALENDARS.