Tabulat

This wooden frame, or tabulat, was used to hold numbering rods known as Napier's bones. The bones were invented by the Scot John Napier (1550-1617). They were used to convert multiplication and division into simpler problems of addition and subtraction.

On the left of the tabulat is a fixed multiplier rod. Using the tabulat it was easier to line up the bones and to ready off the results.

The tabulat was invented after Napier's death. Its use is first recorded in 1648 by a London mathematician, but it probably dates earlier than this.

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