nathanielthecurious:upennmanuscripts:upennmanuscripts:Theorica motus… volvelle on Page 7 of LJS 64,
nathanielthecurious:upennmanuscripts:upennmanuscripts:Theorica motus… volvelle on Page 7 of LJS 64, a manuscript copy of Illustrations to Georg von Peurbach’s Novae theoricae planetarum.Caption in Latin: Theorica motus orbis medii defferens solem neccesario centro eccentrici.My translation: “Theory of the motion of the middle sphere necessarily spreading the center of the sun that is not the center of the orbit.”I sure could use some help with this translation (hint, hint!). Eccentrici seems to be masculine genitive inflection of excentricus, “from Ancient Greek ἔκκεντρος (ékkentros, “not having the earth as the center of an orbit”)” so I think it goes with solem and I’ve translated it quite literally. But I expect there is more to this than a literal translation.In any case, it is a fun volvelle. Enjoy!Another volvelle from LJS 64!What is the second to last word on the first line of the caption? It looks like there’s something between necessario and centro, but I don’t know how to read manuscripts so I don’t know.With medii my instinct in Classical Latin would be to translate “the middle OF THE sphere” because that’s much more often the sense, but based on the image that doesn’t seem tenable. Though admittedly I don’t understand what’s going on in the image, which would definitely help.The only sense I can make of this all is that theorica is treated as singular and is modified by deferens: “a theory that necessarily brings the sun to the center of an eccentric orbit”. (My dictionary lists eccentricus often used substantively. Your definition is good, but for a more readable translation the loan word is probably fine.)The participle is defero, so maybe rather than “bring,” it’s “bring away.”Theorica motus orbis medii defferens solem neccesario centro eccentrici.A theory of the motion of the middle sphere inevitably moving the sun away from the center of its eccentric orbit.This could be a geocentric theory attempting to explain why the “sun’s orbit of the earth” isn’t circular. I think in this case “eccentric” is probably closer to its modern meaning than it is to ἔκκεντρος. According to Wikipedia,The orbital eccentricity of an astronomical object is a parameter that determines the amount by which its orbit around another body deviates from a perfect circle.In light of the diagram, which seems to show the sun orbiting the earth elliptically, this makes more sense than the original Greek definition of a “non-earth-centric orbit.” -- source link