This is a version of Mandeveer’s Patent Arithmetical Table 14 July 1846 improved by J. B. Morill January 1856 and published by J. B. Morill 304 Broadway.
Composed of two concentric cylinders the outer is able to be rotated two show (in the corresponding window) the product of two numbers from 1–12 multiplied together. The cylinders are constructed of cardboard.
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