TO THE

MOST AUGUST

EMPEROR

RUDOLPH THE SECOND

THE PREFACE OF

TYCHO BRAHE.

ASTRONOMY IS THE MOST ANCIENT SCIENCE, granted by God to the human race from the time of Adam the First-Formed original: "Protoplasto", and by far the most excellent, just as celestial and sublime things surpass these earthly and inferior ones. This Divine Astronomy, I say, draws its origin from the very senses of the eyes—which observe the many-wandering successions of the stars—as far as external matters are concerned. From the very beginning of the world, it has occupied the spirits and the intellects of the most excellent men. So great indeed is the majesty of God, the Best and Thrice-Greatest, that the wisdom of His works can be exhausted by no creature. However, since the intuition of the eye alone could not grasp all those mysteries of the wondrous celestial theater, nor the intricate apparent variations, with the necessary subtlety and accuracy, various craftsmen in every age devised means and instruments by which the sight might be aided in perceiving the hidden motions of the stars.

Hence come those pillars which Josephus, the writer of Jewish history, records that the descendants of Adam erected in Syria, and upon which they inscribed their discoveries for the memory of posterity. To this also belong the very high and costly Pyramids of the Egyptians and other nations, and many other machines constructed for this use by ancient kings, such as those that were once seen in India, Syria, Arabia, Chaldea, Ethiopia, and Egypt—especially there in the Alexandrian portico—as well as elsewhere in the surrounding regions where men lived who were diligently intent upon the science of the stars. For this is the first requirement of all: that in astronomical matters, many long-term observations be taken with suitable instruments that are not subject to error. These are afterward digested through Geometry, by devising convenient hypotheses, into continuous quantities and circular, uniform motion (which celestial things naturally and without intermission seek and practice); then, through Arithmetic, they are digested into discrete quantities, so that the circuits and locations of the celestial bodies may be established for any given time.

Among all those who have labored strenuously in this matter, there have reached us at least the records of those things set down by TimocharisAn early 3rd-century BCE Greek astronomer who made some of the earliest recorded observations., Hipparchus, Ptolemy, Albategnius original: "Albategnio," referring to the 9th-century Arab astronomer Al-Battani., King Alfonso, and in the previous age, Copernicus; although the traditions of the two preceding these survive only through some account by Ptolemy. Which instruments these men chiefly used in measuring the phenomena of the stars is somewhat clear from their writings. Among these, I find three principal ones: Parallactic RulesAlso known as the triquetrum, used for determining the zenith distances and altitudes of stars., Zodiacal ArmillariesA series of nested metal rings used to determine the coordinates of celestial bodies relative to the ecliptic., and the TorquetumA medieval instrument used to transform coordinates between the horizon, equatorial, and ecliptic systems., which was used more by the Arabs (as were plane astrolabesHandheld devices used for telling time and solving problems related to the position of the Sun and stars.); the others are of less importance.

Yet perhaps there were many other things which, not being committed to writing, did not reach us; these could easily have perished (which is to be deplored) in such great and frequent confusion and change of the world's stage, with so many wars and devastations creeping in from time to time. More recent men have added the QuadrantA 90-degree arc used to measure the altitude of celestial objects., the RadiusOften called the Cross-staff or Jacob's staff, used for measuring angles between stars., and the Astronomical RingA portable sundial or observational tool consisting of several rings., as well as others of even less esteem. However, since the motions of the stars, when accurately considered in our age, do not at all show themselves to be as the calculation derived from the observations of any craftsmen (whether ancient or recent) suggests, it is not without reason—