Wright · 1768
An Experiment on a Bird in the Air Pump
In the spring of 1768, in his studio at 28 Queen Street in Derby, the thirty-three-year-old Joseph Wright completed the oil painting *An Experiment on a Bird in the Air Pump* (oil on canvas, 183 × 244 cm). The painting shows a itinerant natural-philosopher demonstrating a vacuum experiment to a domestic audience of about seven adults and three children in the late-evening lamp-light of a provincial English house. The vacuum experiment in progress is the air-pump-with-a-glass-globe-and-a-cockatoo, in which the natural-philosopher slowly evacuates the air from the globe and the cockatoo in the globe begins to suffocate; the natural-philosopher can, by re-opening the tap, save the bird. The question of the painting is the moment of the experiment at which the natural-philosopher chooses whether to re-admit the air or to let the cockatoo die for the edification of the audience. The painting is, by every careful judgment of the Enlightenment-art-history (Ronald Paulson, David Solkin, Stephen Daniels), the foundational image of the eighteenth-century English-Enlightenment-encounter-with-experimental-science: the Wright canvas is, in plain reading, the British civilian-domestic version of what Wright had been seeing on his trips to Liverpool and Birmingham among the Lunar Society Enlightenment circle of Erasmus Darwin, Josiah Wedgwood, Matthew Boulton and Joseph Priestley. The painting was bought by Dr Benjamin Bates of Aylesbury in 1768 for £210; it was sold at auction in 1863, bought by the Tate Gallery in 1929, and is, since 1986, in the National Gallery, Trafalgar Square, where it has hung continuously.
It is the late evening of an unrecorded day in March 1768, in the studio at 28 Queen Street in Derby, in the Derbyshire-spring light through the north window. He is thirty-three years old. He is Joseph Wright, born at Iron Gate in Derby on the third of September 1734, son of John Wright the Derby attorney and Hannah Brookes, schooled at the Derby Grammar School, apprenticed in the 1751 London studio of Thomas Hudson (the Reynolds master), settled back in Derby in 1759, in the ninth year of his Derby practice.
The canvas on the easel is the large-format painting (six feet by eight) that he has been working on since the late autumn of 1767. The subject is, by his pre-commission sketches and notes, a natural-philosopher's demonstration of the Robert-Boyle-air-pump-vacuum experiment, in a domestic-provincial setting. The natural-philosopher in the painting is, by the physiognomic-identification of the 1768-Lunar-Society circle, modelled on the young Joseph Priestley (the Yorkshire-Unitarian chemist who was, in 1768, at the Warrington Academy and was in the process of working out the experiments that would lead to the 1774-isolation of oxygen).
He thinks: the painting has to put the moral question of the experiment at the foreground. The question is whether the natural-philosopher will, at the moment of decision, re-admit the air to the globe and save the cockatoo. The cockatoo is the pet of the children in the foreground. The children are watching.
He thinks: the painting is, in plain reading, a genre piece in the Hogarth tradition. The painting is also, by the political-philosophical context of the 1768 Enlightenment, a statement about the moral-character of the scientific experiment. The Enlightenment philosophy of nature is, on the Voltaire-Diderot-Priestley reading, the self-confidence of the scientific revolution in its 1760s mature phase. The Wright canvas, on a careful reading, is the question put to that confidence: the cockatoo's life is in the natural-philosopher's hand, and the natural-philosopher is choosing whether the curiosity-of-the-experiment or the life-of-the-bird is the higher principle.
He thinks: the buyer of the painting is Dr Benjamin Bates of Aylesbury. Dr Bates is a Lunar-Society correspondent and a Priestley friend. Dr Bates will, on the purchase, hang the canvas in his Aylesbury house. The canvas will, in twenty years, become the iconic image of the late-Enlightenment encounter between the scientific revolution and the domestic-bourgeois sentimental conscience of the eighteenth century.
He completes the painting in late March 1768. The canvas is exhibited at the Society of Artists in London in May 1768. The exhibition reception is, by the Annual Register of 1768, the Picture of the Season at the Spring Garden Rooms. Dr Benjamin Bates of Aylesbury bought the painting on the eighteenth of May 1768 for £210 (about £35,000 in 2025 money).
The painting passed through Bates's family at Aylesbury until the 1863 estate sale, at which it was bought by the collector Edward Tyrrell. It was sold by the Tyrrell estate to the Tate Gallery in 1929. It transferred to the National Gallery in 1986 (in the 1986 institutional rationalisation of the pre-1900 British paintings between the two galleries). The 2005 BBC Today programme public poll of the greatest paintings in Britain placed the Air Pump third (after Turner's Fighting Temeraire first and Constable's Hay Wain second). Joseph Wright died at Derby on the twenty-ninth of August 1797, sixty-two years old. He is buried at St Alkmund's church Derby; the church was demolished in 1968 for the Derby ring-road and the Wright grave is, in 2025, beneath the A601 dual-carriageway at the Derby city-centre.