Sir Nicholas Goodison noted: The extended scale suggests that this barometer was conceived as a mountain barometer. Ayscough was an optician and probably did no more then sell barometers. He became a member of the Spectaclemaker's Company in 1740. A trade card in the Heal Collection (British Museum, Heal 105.4) lists barometers and thermometers among his stock at the Great Golden Spectacle. Another trade card, in the Science Museum (inv. no. 1934-101) , advertises 'barometers, diagonal, standard, or portable' (N. Goodison, English Barometers, Woodbridge, 1977, p. 131).