Observatio & demonstratio cometae aetherei, qui anno 1577 et 1578 constitutus in sphaera veneris, apparvit, cum admirandis eius passionibus, varietate scilicet motus, loco, orbe, distantia à terrae centro, &c. adhibitis demonstrationibus geometricis & calculo arithmetico, cuiusmodi de alio quoquam cometa nunquam visa est

from the complaints of learned men, and also from my own experiments, I had understood that something was lacking in the tables of motions and in calculation, even though the reasons for the motions, or hypotheses, were well discovered and demonstrated by the divine ingenuity of the masters, because the calculation itself nonetheless exceeds the face of the sky somewhat, or falls short of it. Therefore, I began to devote myself to this, so that I myself might note many observations in the sky, in case by comparing them with the observations of the most ancient Hipparchus, Ptolemy, Albategny, and the more recent Regiomontanus, Peurbach, Copernicus, and others, I might be able in a short time (if only God grants me life and strength) to restore the calculation to its absolute and long-awaited integrity. Hence it happened that I have always placed Astronomy before Astrology. Wherefore, I can neither arrogantly claim nor do I wish to claim an Astrological judgment for myself here, but I leave that to others, many of whom I see are quite anxious to divine boldly, if indeed this is feasible. Therefore, for this reason, insofar as the Comet is subject to the science of Astronomy, it has been explained by me, so that the Wisdom and omnipotence of God the Best and Greatest may be seen here, just as in other things.

Therefore, Most Illustrious Prince, I offer these lucubrations of mine, which I most submissively offer to Your Highness, and I pray as a suppliant with a submissive mind that Your Highness may receive them graciously. If they do not displease you, as I trust, and if they are not ungrateful to those who love and study Astronomy, for whose sake I have included many things to aid their efforts, I shall understand that I have reaped a most abundant fruit of my labors. May the eternal God, Father of our Savior Jesus Christ, with the Holy Spirit, preserve Your Highness safe and sound for the true Church and Schools for a very long time in these most sad times, grant peace, and oppress all who wish ill to Your Highness and the holy people of God in the Church. Finally, I commend myself to the patronage of Your Highness. Given in Backnang, on Judica Sunday, in the year of salvation 1578.