Sir Nicholas Goodison noted: Patrick appears to have been the first instrument-maker to have specialized in barometers (N. Goodison, English Barometers, Woodbridge, 1977, pp. 46-50 and pp. 197-203).
John Patrick (fl.1686- circa 1720) published a pamphlet 'A New Improvement of the Quicksilver Barometer' (before 1704) accompanied by an advertisement which illustrated a 'sign-post' or diagonal barometer of this type. His barometers, according to the contemporary historian, Charles Leigh, were 'much more exact than any other'. The Duke of Somerset bought one of Patrick's angle barometers together with a pendant barometer in 1701.