[1] The clock consist of a round, square or octagonal wooden base that rises in a tapered column, which is itself surmounted by clockworks that are covered by a glass dome, giving the effect of a standing lighthouse.
Both the form and the respective patented movement (in 1818)[1] were invented by the clockmaker and this timekeeper was devised to offer an alarm mechanism in a high-style shelf clock.
Few original Willard lighthouse clocks have survived and it is estimated that about 200 to 300 examples of this highly sought-after collector timepiece remain.
Regarding the movement, it is an 8-day weight driven, pendulum regulated clock and, as well as the cases, there were a considerable variety of mechanisms in terms of workmanship and design.
To stand out, an unusual exemplary displayed in one of the bookshelves of the White House library, made by the clockmaker to commemorate the visit of the Marquis de Lafayette to the United States in 1824-1825.
[2] Original lighthouse clocks are rare and have become very valuable; for instance one was sold at Sotheby's auction house on January 6, 2006 for US$744,000.