Machines · Study 075
Abacus Clock
A Japanese abacus that shows your local time. Six rods hold hours, minutes and seconds, and the beads slide into place every second.
What you're looking at
Each rod represents one digit. The single bead above the beam is worth five when pushed down to touch it. Each of the four beads below is worth one when pushed up. So seven is the upper bead down plus two lower beads up. The digits underneath show what each rod currently reads.
The idea behind it
This one-and-four layout is the modern soroban, standardised in Japan in the 1930s from older Chinese designs that carried extra beads. Trained users calculate by picturing the beads, and at speed they can outpace someone typing the same sums into a calculator.
Try this
Watch the right-hand rod count seconds: four beads rise one by one, then swap for the upper bead at five.
