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 ...

enters the hole of the second ear. But if, in the first consideration, the ray of the Sun poured through the anterior ear extends below the hole of the posterior ear, the head of the ruler must be moved to the higher part of the sign-bearer, and one must not cease from such repeated inspection and translation of the ruler until the solar ray illuminates the hole of both ears most correctly. But you will understand this little admonition, if you are of mediocre talent, as soon as you begin to handle the instrument. That must not be passed over in oblivion, that when the Sun is near the tropical points, the observations are ambiguous. For if you move the ruler of longitude equally on both sides from the tropical point, the holes of the ears will receive the solar rays equally, and therefore you would not think the Sun is constituted in this place rather than that, unless you simultaneously have found out whether the Sun itself has moved beyond the tropic, or walks on this side. Therefore, having found the place of the Sun as has been handed down, you can simultaneously contemplate the example of the celestial machine in a good part. For the ecliptic circle of the instrument will be correctly constituted in the plane of the celestial ecliptic, unless in so far as the seat of the instrument, being remote from the center of the world, changes it, which interval is indeed almost insensible with respect to the semi-diameter of the solar sphere. Finally, the fabricated Equinoctial circle will lie under the celestial Equinoctial, and the circle of latitude will signify that orbit which, walking through the poles of the zodiac, measures the whole latitude of the sky. Furthermore, you will be able to represent such a configuration of the sky through any other star, provided you do not ignore its true place according to the longitude of the zodiac. For with the ruler of longitude placed over its place in the ecliptic sign-bearer, it will be necessary to rotate the region of the signs to and fro until the center of the star and the center of the eye of the contemplator are constituted in the plane of the circle of latitude; for then you may believe you have fashioned an example of the celestial machine. Moreover, the configuration of the sky will be represented at any given hour in this way: the place of the Sun, considered in the equinoctial sign-bearer, will be placed at the mark of the proposed hour in the equinoctial circuit, and the ruler of longitude [will be placed] over the place