The architect Sir John Soane (d. 1837) helped introduce the picturesque fashion for this form of spherical room-reflecting glass in the late 18th Century, together with the taste for japanning and gilding in the manner of Roman burnished bronze with antiqued green and black enrichments. This fashion was later popularised by patterns engraved in 1804 and issued by the court 'Upholder Extraordinary' George Smith, who wrote, 'In apartments where an extensive view offers itself, these Glasses become an elegant and useful ornament, reflecting objects in beautiful perspective on their convex surfaces; the frames, at the same time form an elegant decoration on the walls, are calculated to support lights'. He also recorded that the profiles to the mouldings should be bold, and noted that 'in general, they will admit of being executed in bronze and gold' (G. Smith, A Collection of Designs for Household Furniture and Interior Decoration, 1808, pl. 135-136).
Amongst Smith's ornaments would have been classical motifs similar to those on the present frame, which allude to the ruling of earth and sea. Jupiter’s eagle, an ancient symbol of power and victory, is perched on an altar plinth, the globes dangling from his beak representing his embodiment of all the powers and function of divinity and his ultimate control. The dolphins issuing candle branches refer to Neptune, ruler of the sea, and Venus, the goddess of love and fertility who was born of the sea.