De revolutionibus orbium coelestium have begun work on his new system by that time. Most historians believe that he wrote the "Commentariolus" after his return from Italy, possibly only after 1510. At this time, Copernicus anticipated that he could reconcile the motion of the Earth with the perceived motions of the planets easily, with fewer motions than were necessary in the "Alfonsine Tables", the version of the Ptolemaic system current at the time. In particular, the heliocentric Copernican model made use of the Urdi Lemma developed in the 13th century by Mu'ayyad al-Din al-'Urdi, the first of the Maragha astronomers to develop a non-Ptolemaic
Myth of the flat Earth flat Earth. The widely circulated engraving of a man poking his head through the firmament surrounding the Earth to view the Empyrean, executed in the style of the 16th century, was published in Camille Flammarion's "L'Atmosphère: Météorologie Populaire" (Paris, 1888, p. 163). The engraving illustrates the statement in the text that a medieval missionary claimed that "he reached the horizon where the Earth and the heavens met". In its original form, the engraving included a decorative border that places it in the 19th century. In later publications, some of which claimed that the engraving dates to the 16th century, the