In "The Orrery", all the subjects have been identified apart from the philosopher, who has physical similarities to Isaac Newton but differs enough to make positive identification impossible. Nicolson detects the strong influence of Frye throughout the picture. Particularly striking is the similarity between Frye's mezzotint "Portrait of a Young Man" of 1760–1761 and the figure of the boy with his head cocked staring intently at the bird. In 1977, Michael Wynne published one of Frye's chalk drawings from around 1760, "An old man leaning on a staff", which is so similar to the observer in the right foreground in Wright's picture to make it impossible that Wright had not seen it. There are other hints of Frye's style in the painting: even the figure of the natural philosopher has touches of Frye's "Figure with Candle". Though Henry Fuseli would later also develop on the style of Frye's work there is no evidence of him having painted anything similar until the early 1780s. So, although he had already been in England at the time the "Air Pump" was produced, it is unlikely that he was an influence on Wright.