Abacus The abacus has a wood frame and a wood back that has a thin vertical split. The corners of the frame have been reinforced with brass strips held by tiny brass nails. Insie the frame the space has been divided into 2 compart- ments by a strip…
Abacus The abacus has a wood frame and a wood back with a split in it; corners reinforced with brass strips and brass nails. Inside the frame the space is divided into two compartments by a strip of wood. 11 pieces of bamboo lie vertically through…
Abacus in Case A: Wood and metal abacus. Wood casing frame with 13 metal rods. Beads are sharp edged with 5 on the bottom tier and one on the top. B: Black cloth over cardboard case open on one end.