Great Britain, London

circa 1820

Santiago James Moore French (master), William Congreve (inventor, patent author)

Brass, wood, shellac, velvet, glass; silvering, gilding, engraving

"Rolling ball" clock, in a purpose-made glazed case, invented and patented by Sir William Congreve in 1808. Clock on inclined plane of the type invented by William Congreve; ball rolling down zigzag grooves in the open frame with columns at the sides; surmounted by three silvered-metal rings indicating seconds, minutes and hours; original Sheraton satinwood case with stepped base and columns surmounted by domed glass hood.