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 ...

...as if handed down from hand to hand, that public gift of celestial doctrine, and both preserved and increased it. And Euripides rightly said that the conversation and collation of doctrine is the parent and inventress of all arts and disciplines. Therefore, since they could not be taught perfectly at the beginning, but grew over the passage of time through one author after another, just as in this most learned age of ours, when these studies of celestial matters had lain entirely abolished and buried without honor for some ages, they revived in Germany through the work of two supreme men, Purbach of Nuremberg and Regiomontanus the Frank, so that they seem scarcely to have had so much light at any other time. It would be a sign of an ungrateful spirit not to respond to such men at least with good will, and not to undertake to exercise and treat with our own studies those things which they produced with the greatest sweats and vigils. A good and diligent father of a family acts with the greatest care so that he leaves as large and magnificent a patrimony as possible to his heirs. How much more should it be the greatest care and study of all good and pious men that we should, first of all, retain the noblest possession of science which philosophy demonstrates, and then also put forth the effort so that, as a most excellent gift of God which has been granted to the human race by divine favor for the sake of the greatest utilities, we transmit it as explained and amplified as possible to posterity. We are not all equally instructed with gifts and talents to help; yet no one in this field should cease, who can bring at least some moment to common affairs. And since, according to the poet, he who is himself unskilled in cutting, should nevertheless not refuse the duty of a whetstone, I judged that it was also my duty that the writings of the most excellent artificers in this field be...