Items22The creator’s order
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AbacusThe abacus stores a number as the positions of movable markers, with each rod or row standing for a place value, so the frame is a memory and the fingers are the processor. Its forms vary, from the Chinese suanpan with two beads above the bar and five below to the Japanese soroban with one above…0 - 2
Antikythera mechanismDivers recovered the corroded remains of this bronze device from a Roman-era shipwreck off the Greek island of Antikythera in 1901. It is the oldest known scientific calculator, and it is about 2,000 years old.
Turn a handle and more than 30 interlocking gears model the heavens: the device could…0 - 3
Napier's bonesJohn Napier described his rods in 1617, the year he died, as a way to turn multiplication into addition. Each rod carries a multiplication table split into squares, and every square is cut by a diagonal with the tens digit of the product above it and the units digit below.
Lay rods for each digit…0 - 4
Slide ruleWilliam Oughtred is widely credited with inventing the slide rule in the 1620s, and his first design was circular. It turns logarithms into distance: because the scales are logarithmic, sliding one bar along another adds lengths, and adding lengths multiplies numbers.
Aligning different scales…0 - 5
Wilhelm SchickardSchickard's calculating machine, about 1623
Wilhelm Schickard, a university professor, minister, astronomer and engraver, built two calculators around 1623 and described one in a letter to his friend Johannes Kepler. His design combined a set of Napier's rods for multiplication and division with a…0 - 6
PascalineBlaise Pascal invented this adding machine in the 1640s to help his father, a tax collector, with endless sums. You entered a digit by putting a stylus into a toothed wheel at that number and turning until it hit a stop, and the machine carried into the next wheel by itself.
That carry was the…0 - 7
Stepped reckonerGottfried Wilhelm Leibniz's Step Reckoner of 1673 is often called the first true four-function calculator. Its secret is the stepped drum, a cylinder whose teeth run partway along its length in graded steps, so that sliding a small gear along it chooses how many teeth it meets. One revolution can…0 - 8
Jacquard machineJoseph Marie Jacquard's loom of 1801 did not calculate anything, yet few machines matter more to this story. It wove patterned textiles by following a chain of large punched cards bound together: where a card had a hole, a hooked rod passed through and lifted its thread, and where it had none, the…0 - 9
ArithmometerThomas de Colmar's Arithmometer, first produced in 1820, is where the calculator became a product rather than a curiosity. Inside, it borrowed Leibniz's stepped drums; outside, it was built to be made in numbers, the first calculator to take advantage of industrial manufacturing.
Early models were…0 - 10
Difference engineCharles Babbage's Difference Engine No. 2
Babbage wanted to end the errors in printed mathematical tables, and the method of differences let him compute a whole table of polynomial values using nothing but addition, which gears do well. He worked on his first engine from 1821, but the project…0
