Shelf Clock

Eli Terry manufactured this clock in 1817 or 1818. Inside its plain box case, the clock features a label with an equation-of-time table for setting clocks with a sundial.
The equation of time refers to the relationship between clock time and sun time. As the relationship of Earth to the sun changes with the seasons, the sun appears to run faster or slower than the clock. The differences between the unvarying clock and the sun accumulate as the year progresses and are charted, like on this clock, as the equation of time.
Terry was one of a handful of a handful of Connecticut inventors and entrepreneurs who transformed the way clocks were made in the United States in the opening years of the 19th century. Recognizing a vast potential market for low-cost domestic clocks, Terry and his associates Seth Thomas and Silas Hoadley applied water-powered machinery to clockmaking. One of the proving grounds of the American Industrial Revolution, clockmaking changed from a craft to a factory process in which machines mass-produced uniform, interchangeable clock parts. This manufacturing technique appeared in other industries about this time and became known as "the American system" of manufacturing.
The process called for a whole new kind of clock. The first mass-produced clocks had movements of wood, instead of scarce and expensive brass. Although the earliest of these wooden clocks had long pendulums and fitted into traditional tall cases, about 1816 Terry designed a distinctly American clock small enough to set on a mantel or shelf. Sold largely to rural buyers by itinerant merchants, these clocks played an early and significant role in transforming the rural North from overwhelmingly agricultural to a modern market society.
Currently not on view
date made
ca 1817
Terry, Eli
Physical Description
wood (case material)
wood (movement material)
overall: 20 1/2 in x 13 7/8 in x 4 in; 52.07 cm x 35.2552 cm x 10.16 cm
ID Number
catalog number
accession number
See more items in
Work and Industry: Mechanisms
Measuring & Mapping
Data Source
National Museum of American History


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