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 ...

We have added this, which for that reason will not be wrongly named the ruler of latitude. That circle of latitude is led in a high position, leaning continuously upon two feet resting on the ruler of longitude. The upper half is inscribed as Northern latitude, and the lower as Southern latitude, with the dividing line reasonably holding the place of the ecliptic. Finally, those smaller ears which we mentioned carry a hanging semicircle, which by its own weight will always seem to seek the horizon perpendicularly, unless it is obstructed. This will be rightly called the semicircle of altitude, because it is accustomed to demonstrate the elevations of stars above the horizon with a perpendicular index. But since the circle of latitude is usually inclined toward both the eastern and western parts of the horizon, and the hanging semicircle must always sway freely, the perpendicular cannot adhere to a single quadrant. Therefore, we have attached one, namely the right one, to the east; and the other, that is the left, to the west, just as the inscriptions advise. Finally, the whole collection of the mentioned parts, which is connected to the ecliptic circle and therefore is carried around with the motion of the ruler of longitude, can be called the crest, for it is believed to bear its appearance, so that you may more clearly understand whatever will be taught below.