The Borghesi Astronomical Clock in the Museum of History and Technology: Contributions from the Museum of History and Technology, Paper 35Bedini, Silvio A.
History
The Borghesi Astronomical Clock in the Museum of History and Technology: Contributions from the Museum of History and Technology, Paper 35
Bedini, Silvio A.
Astronomical clocks
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 common with the ecliptic and subject to absolutely no
motions, but at such a distance from the center of the earth
that the semidiameter of the earth has little, if any,
proportion with the distance of the solar epicycle from the
earth. Around the sun, moving continually in this epicycle (its
immobile palace) through the degrees of the anomaly, you can
revolve, with motions proportionate to the system, the five
planets: Mercury and Venus (the nearest barons of the sun),
then Mars, Jupiter and, most remote, Saturn, with its
respective satellites, etc., eccentrically surrounding the
earth itself and the moon in their immense ambit and wandering
by their proper motions through the zodiac.
Public-domain text, read in full here on John Shaqi.
Reviews
Reviews
No reviews yet
Be the first to share your thoughts on this work.
Join the Discussion
Join the discussion
Sign in to leave a comment or review.
Sign InorCreate an account