Also painted by Plersch was the plafond depicting Apollo in a quadriga. The painting is set in a circular frame, beyond whose perimeters bas-relief-effect medallions bearing the likeness of the outstanding playwrights Sophocles, Shakespeare, Molière and Racine extend. The theatre's interior was built entirely of wood to ensure excellent acoustics. The deep stage has a slanted floor and displays fragments of the equipment of a former engine-room. At either sides of the stage, three-tiered actors’ dressing-rooms were found. In the west wing of the Old Orangery as well as in the corridors running along its main trunk a Gallery of Polish Sculpture has been set up. On exhibit are works dating from the 16th century up to 1939. Only a very few sculptures dating from the 16th and 17th centuries, as well as the first half of the 18th, are on display and they may be admired in Room 1. The next room contains sculptures from the latter half of the 18th century including works by Jan Jerzy Plersch, the artist's father, Franciszek Pinck and Andrzej Le Brun. Dating from the mid-19th century are works by such artist as Paweł Maliński- the first professor of Warsaw University's Chair of Sculpture, Jakub Tatarkiewicz, Władysław Oleszczyński- an outstanding representative of the romantic school, as well as Marceli Guyski and Henryk Sattler, the son of the painter Korneli.