Translated, this is:
By this law the sea waves ebb and flow and lie dormant: When Phoebus and Diana agree in their commands, the waters are moved; when they disagree, the waters lie silent.[16]
Within the central boss of the dial plate, the name of the maker is inscribed:
Bvrghesio Doctore, et Bertolla Limatore Annaniensibvs*
Translated, this is:
[By] Doctor Borghesi and Bertolla, mechanician citizens of Anáuni.
INDICATORS IN THE FRONTISPIECE
There are 12 windows in the frontispiece, through each of which appears an indication relating to time. Beginning at the top of the frontispiece of the dial, the first opening occurs on the breast of the imperial eagle. This indicates the dominating planet, represented by its symbol, and its house.
The opening in the eagle's left claw, labeled "Lit. Dom." is the dominical letter. The first seven days in the month of January are each assigned one of the letters a through g in order of appearance. The letter which coincides with the first Sunday within this period is called the dominical letter, and it serves for the following year. In leap year, two letters are required, one to February 29th and the letter next proceeding for the remainder of the year. This letter is used in connection with establishing the date of Easter Sunday. The date of Easter regulates the dates of the other movable feasts.
The eagle's right claw is labeled "Cyc. EpEC" and represents the epact, or the age of the moon on January 1st. It serves to find the moon's age by indicating the number of days to be added to each lunar year in order to complete a solar year. Twelve lunar months are nearly 11 days short of the solar year, so that the new moons in one year fall 11 days earlier than they did the preceding year. However, 30 days are deducted as an intercalary month since the moon has made a revolution in that time, and the remainder, 3, would be the epact.