The throne consists of a tight pivot which bears the suspension ring. The limb is divided into 360?, numbered in multiples of 10?. On the rete are 29 stars, represented by protruding points. The zodiac circle bears the names of the signs in Latin. The graduated pointer is positioned above the rete and bears the markings '80' '70' '60' '50' '40' '30' '20' '10' '10' '20' '23'.
The back of the astrolabe is divided along its side into four quadrants, each of 90?. These are followed by the signs of the zodiac in Latin, the day of the month, and the months, also in Latin.
In the centre, a double circumference bears the numbers 1 to 28, in an anti-clockwise direction beginning at the circumference. Each number is in a separate box, along with the repeated letters T, S and H.
Between the marks corresponding to the months and the circumference, the lower part of the back of the astrolabe is also marked with four double arcs, which touch each other and are marked with divisions from 2 to 12. The non-graduated pointer, provided with reclining sights and a double hole, completes this face of the astrolabe.
The mater is engraved with three concentric circles. It contains 5 plates, calibrated for the latitudes 40 and 41?, 42 and 43?, 44 and 45?, 46 and 47?, and 48 and 49? respectively.
See M. Miniati, Museo di Storia della scienza: Catalago (Florence, 1991), p.8.