Diagram MAPD0178

Bounded Elongation of Venus Desciptive: The manuscript diagrams for this text and for that following it, the epicyclic explanation of Venus's elongation, are among the most corrupted in all of the Calcidian corpus. The positions of X and K vary extensively, and there are usually two concentric circles within the zodiacal circle, neither of which is called for by the text. However, most scribes either chose not to correct these variants in their exemplars or else did not recognize any error in such variant diagrams. From the eleventh century onward, some scholars did recognize and correct them. The text calls for a severely descriptive, not explanatory, image. The zodiacal circle, a central earth at X, a radius passing through the Sun's center K to the point B, and two radii to two zodiacal points A and Γ, located respectively 50° to the east and to the west of B, are sufficient to complete the diagram. With the Sun always seen along XKB, the planet Venus never appears farther away from it than the two limiting radii XA and XΓ at angles of 50° from XKB.