French mathematician and philosopher who built the machine to help his father, a tax official
Plate 043
1642–1645
Rouen, France
No photograph is shown for this exhibition. The museum displays an image only where it can show the object honestly.
About this date
Blaise Pascal began work in 1642 as a teenager and presented refined machines by 1645. About fifty were built.
About credit
Wilhelm Schickard, in Germany, designed an earlier calculating clock in 1623, but it is known only from letters and a surviving sketch. Pascal’s machines survive.
Chapter II
The world before
Life before the Mechanical Calculator
Sums were done on paper, counting boards or with an abacus. Tax and accounting required repetitive arithmetic.
II
The human achievement
How it came about
Pascal built about fifty machines. Dials were set with a stylus, and an ingenious carry mechanism moved the next wheel on when a dial passed nine. Leibniz later added multiplication in his stepped reckoner (1670s).
III
Understanding the invention
How it works
The Mechanical Calculator, explained in two steps.
01
Step 01 of 02
Geared wheels
Each wheel stands for a digit. Turning it by the right amount adds a number.
Geared wheels
The carry
IV
The transformation
What changed for humanity
Business and tax
Later calculators were widely used in offices.
Ideas about thinking
Philosophers asked whether reasoning could be mechanical.
It showed that arithmetic could be carried out by a machine. Mechanical calculators were later sold to businesses, and the idea ran on to computers.
V
Before and after
Life before and after The Mechanical Calculator
Before
Pen and paper, checking by hand.
After
Setting dials and reading the sum.
On larger screens, drag the divider (or use the arrow keys) to give more room to the world before or after.
