Rhabdological abacus

1822-1824

Japanese abacus with case from the Japanese Chamber of Commerce & Industry

1996

Arithmetical Jewel, 1619.

circa 1619

Charles Cotterell's `Instrument for Arithmeticke' by Robert Jole

1677

Chinese abacus

before 1863

Chinese abacus, "Lotus - flower brand",

1900-1999

Replica of the Salamis abacus, half-size

1978

George Darwin's tidal abacus

1892