Just before he died in 1617, the Scottish mathematician John Napier (better known for his invention of logarithms) developed a set of calculating sticks called 'Napier's Bones.' So named because the sticks were carved from bone or ivory, the 'bones' incorporated the logarithmic system. Napier's Bones were to have a strong influence upon the development of the slide rule (five years later) and subsequent calculating machines which relied upon logarithms.
