otion of the earth. The extent of the universe, however, is
so great that, whereas the distance of the earth from the sun is
considerable in comparison with the size of the other planetary orbits,
it disappears when compared with the sphere of the fixed stars. I hold
this to be more easily comprehensible than when the mind is confused by
an almost endless number of circles, which is necessarily the case with
those who keep the earth in the middle of the universe. Although this
may appear incomprehensible and contrary to the opinion of many, I
shall, if God wills, make it clearer than the sun, at least to those who
are not ignorant of mathematics.

"The order of the spheres is as follows: The first and lightest of all
the spheres is that of the fixed stars, which includes itself and all
others, and hence is motionless as the place in the universe to which
the motion and position of all other stars is referred.

"Then follows the outermost planet, Saturn, which completes its
revolution around the sun in thirty years; next comes Jupiter with a
twelve years' revolution; then Mars, which completes its course in two
years. The fourth one in order is the yearly revolution which includes
the earth with the moon's orbit as an epicycle. In the fifth place is
Venus with a revolution of nine months. The sixth place is taken by
Mercury, which completes its course in eighty days. In the middle of
all stands the sun, and who could wish to place the lamp of this most
beautiful temple in another or better place. Thus, in fact, the sun,
seated upon the royal throne, controls the family of the stars which
circle around him. We find in their order a harmonious connection which
cannot be found elsewhere. Here the attentive observer can see why the
waxing and waning of Jupiter seems greater than with Saturn and smaller
than with Mars, and again greater with Venus than with Mercury. Also,
why Saturn, Jupiter, and Mars are nearer to the earth when they rise
in the evening than when they disappear in the rays of the sun. More
prominently, however, is it seen in the case of Mars, which when it
appears in the heavens at night, seems to equal Jupiter in size, but
soon afterwards is found among the stars of second magnitude. All of
this results from the same cause--namely, from the earth's motion. The
fact that nothing of this is to be seen in the case of the fixed stars
is a proof of their immeasurable distance, which makes even the orbit of
year