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.

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.

[6] The 20th-century art historian Ellis Waterhouse compares these two works to the "genre serieux" of contemporary French drama, as defined by Denis Diderot and Pierre Beaumarchais, a view endorsed by Egerton.

[9] Ferrers purchased the painting, which was exhibited in 1766, for £210, but the 6th Earl auctioned it off, and it is now in the Derby Museum and Art Gallery,[10] where it is on permanent display, close to a working replica of a full-sized mechanical Grand Orrery.

A biographer of Wright, Benedict Nicolson, argued in 1968 that John Whitehurst was the model for the lecturer,[11] while another commentator points out the figure's resemblance to "a painting of Isaac Newton by Godfrey Kneller".