Johannes Werner

This work further developed the suggestion of Regiomontanus that the occurrences of eclipses and cometary orbits could be used to find longitude, giving a practical approach for this method by means of the cross-staff.

His trepidations method to describe precession of the equinoxes De motu octauæ Sphær was posthumously challenged in 1524 by Nicolaus Copernicus in The Letter against Werner.

[2] He is most noted for his work, In Hoc Opere Haec Continentur Nova Translatio Primi Libri Geographicae Cl Ptolomaei, published in Nuremberg in 1514, a translation of Claudius Ptolemy's Geography.

In this work, Werner also proposed an astronomical method to determine longitude, by measuring the position of the moon relative to the background stars.

The idea was later discussed in detail by Petrus Apianus in his Cosmographicus liber (Landshut 1524) and became known as the lunar distance method.