The design of this Palladian pier glass, or 'tabernacle' glass, relates to drawings for mirrors of 1721-22 by the Scottish architect, James Gibbs (1682-1754), who published his designs in his Book of Architecture in 1728. These drawings predate similar designs by Gibbs' contemporaries, William Kent (c.1685-1748), and William Jones (1712-50) who adapted the style for inclusion in The Gentleman's or Builder's Companion of 1739.
The term 'tabernacle' originally referred to a niche in a wall for a statue or bust and derives from antiquity where in classical temples such as the Pantheon in Rome, statues of deities were housed in niches around the walls. According to the furniture historian, Dr. Adam Bowett, the figure of the deity was replaced in mirrors by that of the viewer. There was also a stylistic link between tabernacle mirrors and the rectangular architectural style of wall paneling which made its first appearance around 1720 (Adam Bowett, Early Georgian Furniture 1715-1740, 2009, pp. 294-299).
Extremely fashionable in the second and third decades of the 18th century, this example with its standard classical motifs is unusual for the inclusion of satyr masks in profile that flank the upper part of the frame. Perhaps the most striking comparison to these masks are those featured on the door frames of the Library Closet at Newhailes, East Lothian. These were possibly executed by Flemish craftsmen under the direction of James Gibbs, who is thought to have been employed by Sir David Dalrymple to design the library at Newhailes shortly before Dalrymple's death in 1721 (see John Cornforth, 'Newhailes, East Lothian I', Country Life, 21 November 1996, p.49, fig.7).
Compararable ornamentation is rarely seen on architectural mirror frames although related satyr masks feature on a George II Rococo style mirror of the period (Sotheby's New York, 7 June 1986, lot 166, sold $19,800 including premium). Similar masks also appear on the legs of a carved giltwood table made for the 4th Earl of Arundel, now in the collection of the Portsmouth Museums (ibid., p. 212, plate 5:23), and also on a cabinet stand of circa 1730-40 at Temple Newsam (Christopher Gilbert, Furniture at Temple Newsam House and Lotherton Hall, vol. III, 1998, p. 569, fig. 683). A pair of related 'tabernacle' mirrors sold Christie's London, 5 December 1991, lot 220 (£99,000 including premium).