Atronomical Calculations.

Chapter 11. Approximation. Angles. Mean and true motions. Epoch and location.

Laws 1-4: Visibility calculations are deep. Fixed calendar can be appreciated even by school children in 3 or 4 days.
Laws 5-6: Calculations are simplified/approximated to not fluster the inexprerienced; result - visibility of the moon - is not affected.
Laws 7-9: 360 degrees; 60 minutes, seconds...; order of the 12 constellations.
Laws 10-12: adding/subtracting angles.
Laws 13-14: Velocities are constant. Earth encircled by all the spheres but isn't in the center. Notes 14,15 in Moznaim.
Law 15: Mean and true motion.
Law 16: Epoch.
Law 17: Location: Jerusalem; see Chapter 17.

Chapter 12: Sun and its apogee.

Law 1: Movement of the Sun. Moznaim Note 6: calculations may be accurate only on the first day of the month; Note 7. 59′8.33″ Yale, p.99; Neugeb., p. 388ff
Law 2: Movement of the Sun's apogee. Moznaim Note 10: over 800 years, apogee moved ~12 degrees and is in constellation of Cancer. Note 11: position - at 6PM.

Chapter 13: True position of the sun. True seasons.

Laws 1-3: Tue position of the Sun.
Law 4: Course correction table.
Laws 5-10: Examples.
Law 11: True seasons.

Chapter 14

Law 1: Moon: epicycle and deferent; movement as seen from Earth. See Moznaim notes!
Law 2: Deferrent table.
Law 3: Epicycle table.
Law 4: Epoch.
Law 5: Time of sighting correction table: ~20 minutes after sunset.

Chapter 15

Laws 1-2: Double elongation and its limits. See Moznaim notes!
Laws 3-5: Course correction table.
Laws 4-7: Parallax correction rules and table.
Laws 8-9: Examples.

Chapter 16

Laws 1-4: Head movement, table and rules.
Law 5: Example.
Laws 6-18: Moon latitude.
Law 19: Example.

Chapter 17 (TODO)

Chapter 18 (TODO)

Chapter 19 (TODO)