What is the term for the slight convex bulge on a column to offset the optical illusion that it is hollow or weak?

• A. Entasis
• B. Pedestal
• C. Fluting
• D. Capital

Answer: (A)

Entasis is the intentional convex swelling of a column shaft. It corrects the optical illusion that a perfectly straight shaft looks hollow or weak when seen from a distance. By widening slightly in the middle and then tapering toward the ends, the column reads as solid and sturdy, even though it isn’t perfectly uniform. This technique was widely used in classical architecture, especially Greek temples, to maintain a sense of strength and proportion. The other terms describe different parts or features: a pedestal is the base supporting the column, fluting are the vertical grooves on the shaft, and a capital is the decorative top of the column.