A reproduction of Sir William Congreve’s rolling ball clock by Thwaites & Reed, London, made circa 1972

The lacquered brass case is modelled in the architectural style and the dials for hours, minutes and fifteen-second units are placed within the tympanum below a moulded cornice which is decorated with Anthemion finials. The single fusee movement is enclosed behind the dials and is supported by four reeded Corinthian columns. Within the colonnade is the pivoted table upon which is a zigzag runway. A steel ball travels down the runway until it activates a lever, which releases the train and tilts the table to allow the ball to return. The ball passes through a series of fifteen arches, above which the seconds are numerically indicated. The ball takes approximately fifteen seconds to run from top to the bottom of the table and as the table is tilted the seconds indication changes. The clock has a stepped gilt brass plinth with applied manufacturer’s signature plate over a moulded mahogany base with adjustable brass feet and presentation plaque that reads: ‘Presented to the National Maritime Museum by the Makers, Thwaites & Reed, 1972’


The early 1970s saw a revival of interest in novel horological inventions and companies such as Thwaites & Reed and Dent produced limited editions of various designs. William Congreve (1772-1828) is better known for developing solid fuel rockets that were used effectively against the Americans in the War of 1812.