Rapid Calculator

"Manufacturer: S.W. Allen Company. 20 South Eighteenth St., Philadelphia. The machine is said to have been manufactured since 1918. Reports of sales in larger numbers date from 1923. It is a pinwheel machine produced with either 8 x 9 x 13 places or 9 x 10 x 18 places. It weighs 4.5 kg." Ernst Martin, "The Calculating Machines."

Source: Courtesy of Anthony

X-Number World