t were, at a single point.

XVII. And as I continued to observe the earth with great attention, How
long, I pray you, said Africanus, will your mind be fixed on that
object? why don't you rather take a view of the magnificent temples
among which you have arrived? The universe is composed of nine circles,
or rather spheres, one of which is the heavenly one, and is exterior to
all the rest, which it embraces; being itself the Supreme God, and
bounding and containing the whole. In it are fixed those stars which
revolve with never-varying courses. Below this are seven other spheres,
which revolve in a contrary direction to that of the heavens. One of
these is occupied by the globe which on earth they call Saturn. Next to
that is the star of Jupiter, so benign and salutary to mankind. The
third in order is that fiery and terrible planet called Mars. Below
this, again, almost in the middle region, is the sun--the leader,
governor, and prince of the other luminaries; the soul of the world,
which it regulates and illumines; being of such vast size that it
pervades and gives light to all places. Then follow Venus and Mercury,
which attend, as it were, on the sun. Lastly, the moon, which shines
only in the reflected beams of the sun, moves in the lowest sphere of
all. Below this, if we except that gift of the Gods, the soul, which
has been given by the liberality of the Gods to the human race,
everything is mortal, and tends to dissolution; but above the moon all
is eternal. For the earth, which is the ninth globe, and occupies the
centre, is immovable, and, being the lowest, all others gravitate
towards it.

XVIII. When I had recovered myself from the astonishment occasioned by
such a wonderful prospect, I thus addressed Africanus: Pray what is
this sound that strikes my ears in so loud and agreeable a manner? To
which he replied: It is that which is called the _music of the
spheres_, being produced by their motion and impulse; and being formed
by unequal intervals, but such as are divided according to the justest
proportion, it produces, by duly tempering acute with grave sounds,
various concerts of harmony. For it is impossible that motions so great
should be performed without any noise; and it is agreeable to nature
that the extremes on one side should produce sharp, and on the other
flat sounds. For which reason the sphere of the fixed stars, being the
highest, and being carried with a more rapid velocity, moves with a
shr