TLF ID R1783
This is a rectangular wooden abacus (15.5 cm x 29 cm x 2.5 cm), made in about 1900. It has two decks (divided horizontally by the beam) of 13 rods inserted vertically in the frame. On the bottom deck there are five wooden beads on each rod and on the top deck there are two beads on each rod. The abacus has a removable wooden backing (not shown) that slides from one side. It was made in China and used on the Adams Flat Chinese gold field, Central Otago, in the South Island of New Zealand.