twelve carved wooden figures of angels are located among the beams holding items that reference the arts and sciences ­– grammar has a papyrus roll, dialectic has aristotle’s diagram of the three syllogistic figures, poetry has a harp, ethics has a st mary’s lily, metaphysics has a symbol of the deity, arithmetic has an abacus, geometry has the 47th proposition of the first book of euclid, astronomy has a star, music has a lyre, and physics has an ancient air pump. an angel of knowledge originally sat atop the eastern gable, however was removed in 1874.