Jupiter utque respectu fixarum revolvitur horis 9 56’ (novem et quinquaginta sex minutis)
mars horis 24 39’ (vigintiquatuor et triginta novem minutis), venus horis 23 (vigintitres) circiter,
terra horis 23 56’ (vigintitres et quinquaginta sex minutis), sol diebus 25 1/2 (vigintiquinque et dimidium) et luna diebus 27 (vigintiseptem) horis 43’ (quadraginta tres minutis).
Haec ita se habere ex phaenomenis manifestum est.
Maculae in corpore solis ad eundem situm in disco solis redeunt diebus 27 1/2 (vigintiseptem et dimidium) circiter,
Respectu terrae;
Ideoque respectu fixarum sol revolvitur diebus 25 1/2 (vigintiquinque et dimidium) circiter.

Simili motu extimus saturni satelles circa axem suum revolvi videtur,
Eadem sui facie saturnum perpetuo respiciens.

Nam circum saturnum revolvendo,
Quoties ad orbis sui partem orientalem accedit,
Aegerrime videtur et plerumque videri cessat:
Id quod evenire potest per maculas quasdam in ea corporis parte quae terrae tunc obvertitur, ut Cassinus notavit.

Simili etiam motu satelles extimus jovialis circa axem suum revolvi videtur,
propterea quod in parte corporis jovi aversa maculam habeat quae taquam in corpore jovis cernitur ubicunque satelles inter jovem et oculos nostros transit.

With respect to the fixed stars Jupiter revolves in 9 hours 56 minutes, Mars in 24 hours 39 minutes, Venus in about 23 hours, the earth in 23 hours 56 minutes, the sun in 25 1/2 days, and the moon in 27 days 7 hours 43 minutes. That these things are so is clear from phenomena. With respect to the earth, the spots on the body of the sun return to the same place on the sun’s disc in about 27 1/2 days; and therefore with respect to the fixed stars the sun revolves in about 25 1/2 days.

The outermost satellite of Saturn seems to revolve about its own axis with a motion similar to our moon’s, constantly presenting the same aspect toward Saturn. For in revolving about Saturn, whenever it approaches the eastern part of its own orbit, it is barely seen and for the most part disappears from sight; and possibly this occurs because of certain spots in that part of its body which is then turned toward the earth, as Cassini noted. The outermost satellite of Jupiter also seems to revolve about its own axis with a similar motion, because in that part of its body turned away from Jupiter it has a spot which, whenever the satellite passes between Jupiter and our eyes, appears as if it were on the body of Jupiter.