Napiers Bones A method invented by Baron Napier, of Merchiston, for shortening the labour of
trignometrical calculations. Certain figures are arranged on little slips of paper or ivory, and simply by
shifting these slips the result required is obtained. They are called bones because the baron used bone or
ivory rods instead of cardboard.

If I remember correctly, Napier was one of the first people to use logarithms to simplify
multiplication. His "bones" were precursor of slide rule, which few AWADtalk participants
ever used. What a blessing electronic calculators are.