Displayed on the desk are a planisphere from the Cabinet of Peter the Great - a 17th-century device used to determine the rising and setting times of celestial bodies, a bronze candlestick and an imitation book in a leather binding with a metal clasp. Such trick representations of objects were very common in the 18th century - books carved from wood and painted, figures of female servants or Moors might be used to indicate the function of a room or which way to go, or as a replacement for the real thing.