Across
- 4. – A simple sundial used for timekeeping.
- 5. – A model of the celestial sphere with rings representing astronomical circles.
- 7. – A branch of mathematics dealing with angles and triangles.
- 8. – A water clock used in ancient times to measure time.
- 9. – An ancient surveying and astronomical instrument.
- 10. – An early instrument projecting the celestial sphere onto a flat surface.
Down
- 1. – A method of mapping a spherical surface onto a flat plane.
- 2. – Ptolemy’s influential work on astronomy and mathematics.
- 3. – A historical astronomical instrument used for navigation and timekeeping.
- 6. – An imaginary sphere surrounding Earth, used to map stars and planets.