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 patent model for a circular adder has a wooden base that supports three concentric wooden rings and a central mechanism. The outer fixed ring is serrated around the outer edge. The 100 serrations are numbered in ink from 1 to 99 (the 0 serration isn’t numbered) on a paper ring glued to the surface of the ring. Inside this ring is a movable ring, with 100 upward-facing serrations around its edge. These are numbered on an adjacent piece of paper from 00 to 99. Inside this ring is a third fixed ring, serrated on the inside, and also carrying a numbered slip of paper numbered from 00 to 99.
- Two wooden arms are mounted on a rotating wooden platform at the center of the instrument. The larger arm is designed to link to the two outer rings and the smaller one to the middle ring only. The machine has a carry from the tens to the hundreds place. It is intended to be used for adding columns of figures, two places at a time. The machine was patented by Elmore W. Taylor of Franklin, Indiana, in 1874.
- Earlier, Elmore W. Taylor of Franklin, Indiana, took out patent 56464 for an evaporator (relating to furnaces) on July 17, 1866. Elmore W. Taylor of Detroit, Michigan, took out a patent for a card and picture holder in 1883 (#274052). Elmore W. Taylor of Johnson County, Indiana, married Maggie A. Toner on October 5, 1876. The 1880 US Census lists an “Elmer W. Taylor,” photographer, age 31, born in Michigan with parents born in New York, who was living in Detroit with Margaret A. Taylor, age 21, who was born in Indiana. Hence it seems likely that all three patents were held by the same inventor.
- Reference: U.S. Patent 155772, October 6, 1874.
- Currently not on view
- date made
- Taylor, Elmore W.
- Taylor, Elmore W.
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- accession number
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- Data Source
- National Museum of American History, Kenneth E. Behring Center