The three inscriptions refer to the end of the world, calculating that it will last for 19,683 years. The Latin inscriptions can be translated as:
In the year of Christ one thousand two hundred and twelve plus sixty minus four, the third King Henry, the city, Odoricus and the abbot put these porphyry stones together.
If the reader wisely considers all that is laid down, he will find here the end of the primum mobile; a hedge (lives for) three years, add dogs and horses and men, stags and ravens, eagles, enormous whales, the world: each one following triples the years of the one before.
The spherical globe here shows the archetypal macrocosm.