t is about to move towards one, the opposite power is
constantly drawing it back. Thus, both those points and the
axis of the earth are always held in one common line, wherever
those points happen to be carried by the rotation of this
heaven.

Again, it is necessary for you to conceive in this heaven,
first, two great circles, bisecting each other at right angles
in the centers of these two magnets. One of these circles,
passing through the first point of Aries and Libra in the
ecliptic, is called equinoctial colure: the other circle,
passing consequently between the first point of Cancer and
Capricorn, is called solstitial colure. Beneath these are
likewise imagined many other great circles, in the centers of
the magnets dividing crosswise in the shape of an "X." But if,
receding from these magnets, you describe circles (parallel to
each other and ever greater and greater, up to the greatest
circle which you will perceive is called the equator),
equidistant from each magnet and obliquely splitting the
ecliptic in the equinoctial colure, you can then behold a
great, new, woven net in this heaven of the Primum Mobile. This
net most beautifully expands to extract the straight ascent and
descent of the stars, etc., from the vast ocean of the heavens,
catching the straight ascent in the greatest circles and, in
other unequal circles, parallel to each other and obliquely
cutting across, most safely catching the descent.

Immediately below the Primum Mobile place the heaven of the
fixed stars (and, that the idea might be clearer), revolving
separately on the same poles on which the Primum Mobile
revolves. Through this heaven, the filaments of the little
nets, etc., seem to the eyes of you on earth as if they shine.
In this heaven, you should conceive in their fixed places, the
fixed stars, a proportionate, inviolable distance from each
other, and, indeed, if you will, the heavenly images, etc.,
depicted, and all carried along at the same time with their
heaven by one motion.

Conceive a straight line running from the center of the earth
to that sign "o" noted in the semicircle of the supreme
immobile heaven. On this line, greatly below the heaven of the
fixed stars, place the center of the solar epicycle, holding an
area in commo