A: Paris, Île-de-France, France

1671

In *Dissertations academiques. . . avec un discours sur. . . un cylindre arithmetique* published in Paris in 1671, Pierre Petit described an arithmetic cylinder, which he said was more affordable and easier to use than Pascal’s Pascaline.

John Napier (1550-1617) invented several mechanical methods to simplify and speed up the arithmetic calculations, especially multiplication. His most famous invention was his *Napier Rods*, later known as Napier’s Bones. Pierre Petit improved on Napier’s Bones by devising an arithmetic cylinder using long bands of paper strips with all of the multiples of John Napier’s rabdology. The long bands were then attached end to end and mounted on a wooden cylinder the size of a child's drum or a hat. The reckoning principles were identical to Napier's bones.