On some adders, numbers were represented along an arc of a circle. People used their fingers or a stylus to enter numbers. On a few of these instruments, a mechanism allowed one to carry a single digit. These objects are described here as adders with carry. They blur the line between adders and adding machines.
"Adders - Circular Adders" showing 1 items.
- This U.S. Patent Office model for an adder has a square wooden frame. On top is a piece of paper printed with the numbers from 1 to 100 and a rotating tin disc. The disc has 100 holes in it and is covered with another piece of paper, with the digits from 1 to 100 printed around the edge. Atop this disc is a second, smaller wooden disc with ten serrations around the edge. There also is a fixed metal arm which reaches over the 100 disc on the outside paper. This arm advances the smaller disc at every rotation of the larger disc.
- Census records suggest that the inventor of this device was born in Connecticut or Massachusetts in about 1813. The 1840 U.S. Census indicates that there was a William M. Briggs, 20 to 30 years old, living with a woman of about the same age and two children in Stoughton, Norfolk County, Massachusetts. No record for William Briggs was found in the 1850 census for Massachusetts. The 1860 Census returns list a William Briggs, 47 years old and a farmer, living with Elizabeth, 32 years old, and children Emma (10), Frank (5), and George (2). This William Briggs was supposedly born in Massachusetts. The family lived in Sharon, Norfolk County, Massachusetts, a town very close to Stoughton, Massachusetts. In the 1870 Census for Stoughton, Norfolk County, Massachusetts, there was a William M. Briggs, miller, 57 years old, born in Connecticut. He reportedly lived with Elizabeth (age 43) and a five-year old boy.
- References: U.S. Patent 222,126, December 2, 1879.
- P. Kidwell, “Adders Made and Used in the United States,” Rittenhouse, 1994, 8:78-96.
- Currently not on view
- date made
- Briggs, William M.
- Briggs, William M.
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- accession number
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- Data Source
- National Museum of American History, Kenneth E. Behring Center