The Earth appears to us as a large circular disk, and the sky as a vault resting on this disk. The circular line that marks the boundary between this disk and the celestial vault in flat areas is called the horizon. A vertical line, established at the center of the disk, meets the vault at its highest point, the apex or zenith. With the book "Astronomy: Size, Motion, and Distance of Celestial Bodies," August Ferdinand Möbius presents a well-founded introductory work on 19th-century astronomy. The work is divided into six sequential chapters. Möbius begins his presentation with the Earth, then moves on to the Moon and the other planets, concluding the book with a discussion of comets, meteors, and fixed stars. The author consistently contrasts the scientific description of the processes involved.