Scripta clarissimi mathematici M. Ioannis Regiomontani, de torqueto, astrolabio armillari, regula magna ptolemaica, baculo[que] astronomico, & observationibus cometarum, aucta necessariis, Ioannis Schoneri ... additionibus. Item observationes motuum solis, ac stellarum tam fixarum [qua ...] erraticarum. Item libellus M. Georgii Purbachii de quadrato geometrico ...

...preserved, and that they be brought to light by me for the public utility of studies. And now also, when I saw that these little books of Regiomontanus, which have long lain hidden among us, were perhaps going to perish, either because of the difficulty of reading or the ignorance of those into whose hands they might come after my death: I decided to bring them to light especially under the auspices of your name, partly because they were born long ago within the walls of your city, and partly because I received them from you with the instruction that we should communicate to students those things which seemed useful for public studies. Furthermore, nothing more useful can be taught in the entire doctrine concerning the motions of celestial bodies than these five astronomical instruments: the Torquetum, the Armillary Astrolabe, the Great Ptolemaic Rule, the Astronomical Staff, and the Geometric Square, whose composition and use these books contain, along with the motions of the Sun and the stars, both fixed and wandering, and finally also the comets, which were long ago observed through these organs. Since observations are the foundations of these most excellent disciplines, which are made not by just anyone, but by excellent artificers; it is most useful for adolescents to be accustomed, by the examples and precepts of great men, to the legitimate handling of these instruments, with which the greatest artificers observed the celestial motions. And for that reason, we have added to the rest of the work a not-to-be-despised Treasure of observations, which we found most sacredly hidden and most diligently fortified in a certain casket, so that through these examples, as it were, it might appear by what method the supreme men, and those most skilled in mathematical matters, investigating the most beautiful lights of the sky, investigated, established, and noted their certain and perpetual courses, intervals, and limits, finally...