Antique Regency Rotating Book Shelf. This antique Regency bookshelf measures 30 and one quarter inches high, overall. The top shelf measures 16 inches in diameter across, and the shelf is 7 and three quarter inches high. The bottom shelf measures 18 and one quarter inches in diameter and is 8 and three quarter inches high, inside. This rotating bookcase has brass heavy solid brass casters and book matched mahogany veneer c1910.