The Grotesque Abacus of Nethaneel Fourin is a 1870 years old piece made by Nethaneel Fourin, a merchant living in Istanbul / Constantinople / Byzantium.
Considering its age and the quality of the work, people consider it of some value.
It is engraved with central asian patterns and some symbols pertaining to Sufism.
Though exposed in this museum, this piece belongs to the last of the Fourin family, Chatur, currently living in Mumbai.