Horizontal Pedestal Sundial - Cannon Dial

Horizontal Pedestal Sundial - Cannon Dial

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Description
This cannon sundial consists of a round marble base, two brass supports for a magnifying glass, and a brass cannon. A dial calibrated from 7 to 12 to 5 by 1 for a latitude of 43 degrees is carved into the marble base. A hole within the dial held a blade gnomon for indicating the local time. The gnomon for this dial is missing. One of the supports for the magnifying glass is calibrated with the months of the year. Knurled thumb screws in each of the supports allow the hinged magnifying glass to be adjusted for the calendar date so that the rays of the sun would be focused onto the touch hole of the cannon. At local apparent noon, the sun rays would ignite a few grains of black powder and cause the gun to fire. Victor Chevalier (1770-1841), a Parisian instrument maker, has been credited with patenting the cannon sundial. This particular instrument dates to the 1800s; its maker is unknown.
Location
Currently not on view
Object Name
sundial, horizontal pedestal
date made
1800-1860
Measurements
overall: 22 cm x 27.3 cm x 27.3 cm; 8 21/32 in x 10 3/4 in x 10 3/4 in
ID Number
MA.319081
catalog number
319081
accession number
236085
subject
Mathematics
Timekeeping
See more items in
Medicine and Science: Mathematics
Science & Mathematics
Data Source
National Museum of American History
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