Dungal Letterato E Astronomo. Note di stilistica e di astronomia sulla   Lettera a Carlo Magno circa le eclissi di sole dell'810
  D\'ungal's letter to Charlemagne on the double solar eclipse in the year 810 is extremely interesting both for its form and for its subject matter. Part I of the present study deals with the epistula as a literary work (genre, language, sources), dealing in turn with vocabulary, morphology and syntax, rythmical prose and rhetorical figures, literary and Biblical references. If we compare it with D\'ungal's other works, the letter is cast in the canonical oratio structure similar to his later Responsa contra Claudium (ed. Zanna, Firenze 2002) and it is likewise based on lengthy quotations drawns from Macrobius' commentary In Somnium Scipionis. A possible echo of Vitruvius' astronomical presentation in book IX of his De architectura is suggested. Finally, we attempt to define how the author's persona as famulus et orator and reclusus at St-Denis relates to Charlemagne and to abbot Waldo in his pursuit of Chirstian wisdom based on the Bible rahter than of scholarship per se based on academic research. Part II is a thorough technical discussion of the astronomical issue presented to the Irish scholar by the Emperor, i.e. The frequency of solar eclipses and their visibility in the two emispheres in the year 810 (see maps provided). It assesses D\'ungal's case in terms of eclipse theory and reviews previous comments on his letter to Charlemagne by astronomer Ismael Bullialdus (1605-1694). It also introduces us to first-hand knowledge of eclipses in history and nowadays, providing a glimpse into the complex problems tackled by the Irishman and his sources in Late Antique and in the Early Middle Ages. Ample footnotes to the Italian translation of D\'ungal's work are an essential guiding tool for Latinists unfamiliar with astronomy. 
Paolo Zanna and Costantino Sigismondi
physics.hist-ph astro-ph.IM