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 (National Gallery, London). The first of Wright's candlelit masterpieces, Three Persons Viewing the Gladiator by Candlelight, was painted in 1765, and showed three men studying a small copy of the "Borghese Gladiator". The Gladiator was greatly admired; but his next painting, The Orrery, caused a greater stir, as it replaced the Classical subject at the centre of the scene with one of a scientific nature. Wright's depiction of the awe produced by scientific "miracles" marked a break with previous traditions in which the artistic depiction of such wonder was reserved for religious events, since to Wright the marvels of the technological age were as awe-inspiring as the subjects of the great religious paintings. In both of these works, the candlelit setting had a realist justification. Viewing sculpture by candlelight, when the contours showed well, and there might even be an impression of movement from the flickering light, was a fashionable practice described by Goethe. In the orrery demonstration the shadows cast by the lamp representing the sun were an essential part of the display. But there seems no reason other than heightened drama to stage the air pump experiment in a room lit by a single candle, and in two later paintings of the subject by Charles-Amédée-Philippe van Loo the lighting is normal. Context The painting was one of a number of British works challenging the set categories of the rigid, French-dictated, hierarchy of genres in the late 18th century, as other types of painting aspired to be treated as seriously as the costumed history painting of a Classical or mythological subject. In some respects the Orrery and Air Pump subjects resembled conversation pieces, then largely a form of middle-class portraiture, though soon to be given new status when Johann Zoffany began to paint the royal family in about 1766. Given their solemn atmosphere however, and as it seems none of the figures are intended to