Napier's Bones. It was a type of abacus.
Abacus
by John Napier in 1617
John Napier
The Inventor Of Early Abacus Was Napier Bones.
Because he wanted a simple calculating device. (It's "bones" actually.)
To have a type of abacus to use.
The abacus was invented several thousand years ago. There was nobody around to take a picture of the inventors. The forerunner of the camera was invented less than 200 years ago.
in the 17th century
Fingers, Quipu, Pebble Computer, Abacus, Napier's Bones
Abacus --> Napier's Bones --> Pascaline --> Leibnitz's Calculator --> Jacquard's Loom --> Babbage's Difference Engine --> Babbage's Analytical Engine --> Hollerith's Machine --> Mark I
Babbage