A Philosopher Lecturing on the Orrery, or the full title, A Philosopher giving that Lecture on the Orrery in which a lamp is put in place of the Sun, is a 1766 painting by Joseph Wright of Derby depicting a lecturer giving a demonstration of an orrery – a mechanical model of the Solar System – to a small audience. It is now in the Derby Museum and Art Gallery. The painting preceded his similar An Experiment on a Bird in the Air Pump. Joseph Wright of Derby, 1766 — painted at 32. Canvas and oil paint. 147.2 × 203.2 cm. In the Derby Museum and Art Gallery. Wiki link