Allen's Astrolabe

Allen's Astrolabe is a historical navigational instrument used to measure the height of celestial objects, like stars and planets, above the horizon. By doing so, it helps determine the user's location and time of day or year. The device consists of a disk with marked scales and movable parts that align with specific stars or the Sun. When used properly, it allows sailors and astronomers to perform important calculations for navigation and celestial observation, making it an essential tool before modern GPS technology.