Apart from the French-headed arch which derives from those that Daniel Marot illustrated in his Oeuvres, 1712, the urn and architecture reflects the Palladian or antique manner introduced by James Gibbs' Book of Architetcure, 1728. Its dome is also embellished in the French manner with trompe l'oeil simulated brass inlay of foliage and this corresponds to the ribbon-scrolled engraving of the dial. The latter's Venus-shell spandrels and richly fretted cartouche featured in A New Book of Shields published in the late 1720s after Jean Duvivier (see: M. Snodin, 'Thomas Bowles', Furniture History, Leeds, 1994, p. 89, fig. 6).
A wheel-barometer signed by John Bastard is now in the Dorset County Museum (see: P. Legg, 'The Bastards of Blandford', Furniture History, 1994, p. 23, fig. 4). William and John inherited their father's workshops in 1720 and erected new premises in Blandford following a fire in 1731. They acted as archtiects, joiners and cabinet-makers as well as supplying clocks and barometers. One of the Bastards' mahogany 'weather-glasses' was purchased in 1732 for Wimborne St Giles by the Earl of Shaftesbury. Another inscribed by William Bastard in an ebony-japanned was purchased by Sir James Howe (d. 1736) of Cold Barwich, Wiltshire (see: Legg, loc. cit., fig. 4)