Mathematical Treasure: Oronce Fine’s Manuscript on Finding Longitude with a Lunar Instrument

Among the surviving works of Oronce Fine (1494–1555) is a 1543 manuscript, L'art et manière de trouver certainement la longitude de tous lieux sur la Terre par le cours et mouvement de la Lune et La composition et usage d'un singulier méthéoroscope géographique (The art and manner of finding certainly the longitude of all places on the Earth by the course and movement of the Moon and The composition and use of a singular geographical meteoroscope). As the title suggests, Fine presented an instrument for obtaining celestial measurements, from which he computed the longitude of a location. The use of lunar distances was a common technique during this period in the history of longitude.

Some pages from this manuscript:

The images above are presented courtesy of Bibliothèque nationale de France (BnF), which offers a complete digitization via Gallica. Fine is well-represented in Mathematical Treasures; see a list of works in the discussion of his De arithmetica practica as well as the collection index below.

Index to Mathematical Treasures