Note 783 — BOOK XI.
Thomas Hodgkin translation
As might be expected from an observer who did not understand the earth's motion in its orbit, the periods assigned to the inferior planets in this paragraph are all wrong, while those assigned to the superior planets are pretty nearly right.
Periods according to Cassiodorus. True Periods.
Saturn 30 years 29 years 174 days.
Jupiter 12 " 11 " 317 "
Mars 1 year 182 days 1 year 321 "
Venus 1 " 91 " 224 "
Mercury 1 " 30 " 88 "