N The 12 signs of the sun's anomaly;
O, P The first chapter ring representing the equatorial globe of the
week, revolving from left to right;
Q The coming day indicated through the window;
R The second chapter ring; including the synodic-periodic measure of
the tides, the days of the median lunar-synodic age, the signs and
degrees of the signs for mean distance of the moon from the sun;
S Epicycle of the moon with signs of its anomaly;
T Head of the dragon (Cap. Draconis);
U Tail of the dragon (Cauda Draconis), for measuring eclipses of the
earth and of the moon;
V Third chapter ring, with degrees of lunar latitude and some fixed
stars;
W Fourth chapter ring, showing firmament of fixed stars, signs of the
zodiac and degrees of the signs, the months of the year, and days of the
months, revolving left to right for the course of a mean astronomical
year;
X Adjustment marked _Claudit_ (it closes) and _Aperit_ (it opens) for
disengaging dial work for the purpose of making astronomical experiments
and computations;
Y Adjustment marked _Concitat_ (it accelerates) and _Retardit_ (it
retards) for fast and slow adjustments of the movement.
In the upper spandrels of the dial are two more cherubs bearing ribands
with inscriptions. In the lower left corner is a magnificent engraving
of Atlas upholding the globe of the world, inscribed with the zodiac,
over his head. The lower right corner features the figures of two
noblemen apparently examining and discussing an orb upon a table, the
significance of which is not clear.
[Illustration: Figure 12.--EMPRESS MARIA THERESA, to whom Father
Borghesi is stated to have presented his two astronomical clocks. The
coin bearing her portrait is in the Museum of History and Technology.]