- DOI:
- 10.17171/1-2-097-1
- Citation:
- Gerd Graßhoff, Hans-Christoph Liess, Domenico Schneider, Diagram MAPD0097, 2015, Medieval Diagrams, edition topoi, DOI: 10.17171/1-2-097-1
- License:
- Bamberg SB
>
10.17171/1-2-097-1
Diagram MAPD0097
Gerd Graßhoff, Hans-Christoph Liess, Domenico Schneider
edition topoi
2015
Bounded Elongation of Venus Epicyclic: The manuscript diagrams for this text are often confusing, and it is less easy to categorize them than the diagrams for the previous text, which gives the observational account of Venus's elongation. As the text says, the epicyclic explanation builds upon the immediately preceding text that describes the visible elongation. However, with the positions of X and K already misplaced in most of the diagrams for the prior text, any attempt to add an epicyclic circle for Venus would usually result in further error. Nonetheless, certain scholars of the eleventh century did reconstruct the diagrams correctly from the text. The epicyclical account of Venus's elongation prescribes a circle cutting the zodiacal radius XKB. This radius passes from the earth through the Sun at K, but the distance from X to K is nowhere stated. While it would seem proper to make this radius bisect the epicyclic circle, the location of K is possible at the center of the epicycle, below this center, or completely outside and below the epicycle. The last option would fit Plato's planetary order, which has Venus farther than the Sun from the earth. In any case, Calcidius does not specify the location of K with respect to the epicycle. The main purpose of the epicycle is not to show the order of planets but to show the limited movement of Venus with respect to the Sun, and the account does this. The epicycle ΔEZH is drawn into the preexisting diagram for the simple phenomenal description so that the epicycle fits between the zodiacal circle ABΓ and its center X and is tangent to the two preset radii XA and XΓ, which pass to points 50° to either side of the zodiacal point B.
Diagram MAPD0097
Gerd Graßhoff, Hans-Christoph Liess, Domenico Schneider
edition topoi
2015
Bounded Elongation of Venus Epicyclic: The manuscript diagrams for this text are often confusing, and it is less easy to categorize them than the diagrams for the previous text, which gives the observational account of Venus's elongation. As the text says, the epicyclic explanation builds upon the immediately preceding text that describes the visible elongation. However, with the positions of X and K already misplaced in most of the diagrams for the prior text, any attempt to add an epicyclic circle for Venus would usually result in further error. Nonetheless, certain scholars of the eleventh century did reconstruct the diagrams correctly from the text. The epicyclical account of Venus's elongation prescribes a circle cutting the zodiacal radius XKB. This radius passes from the earth through the Sun at K, but the distance from X to K is nowhere stated. While it would seem proper to make this radius bisect the epicyclic circle, the location of K is possible at the center of the epicycle, below this center, or completely outside and below the epicycle. The last option would fit Plato's planetary order, which has Venus farther than the Sun from the earth. In any case, Calcidius does not specify the location of K with respect to the epicycle. The main purpose of the epicycle is not to show the order of planets but to show the limited movement of Venus with respect to the Sun, and the account does this. The epicycle ΔEZH is drawn into the preexisting diagram for the simple phenomenal description so that the epicycle fits between the zodiacal circle ABΓ and its center X and is tangent to the two preset radii XA and XΓ, which pass to points 50° to either side of the zodiacal point B.
JPEG
Eastwoodcollection
Image
Gerd Graßhoff
Digilib
2015
1.5 MB
Eastwoodcollection
Image
Gerd Graßhoff
Digilib
2015
1.5 MB
Exzellenzcluster 264 - Topoi
Bamberg SB, Ms Class. 18, f.34v
10.17171/1-2-097
Bamberg SB, Ms Class. 18, f.34v
10.17171/1-2-097
Bamberg SB