Simultaneous Risings and Settings in De le Stelle Fisse

In the last section of De le Stelle Fisse Piccolomini presents a list with data on the co-rising and co-setting of each constellation and the ecliptic. He also lists the point on the ecliptic that intersects the local meridian when a constellation culminates. This chapter considers how reliable Piccolomini’s data are. As for the ways in which Piccolomini might have acquired his data, one can only speculate since he is silent about it. However, his descriptions strongly suggest that he used figurative images of the constellations which would point to his use of a globe in composing his data on simultaneous risings and settings.