A Victorian-era mechanical calculator could solve complex equations using thousands of gears

In the early 1820s, mathematician Charles Babbage set out to eliminate human error from navigation and engineering tables by building the Difference Engine. This massive mechanical computer utilized a series of toothed wheels to perform addition through the 'method of finite differences.' By turning a hand crank, the machine could calculate polynomials and logarithms to 31 decimal places, producing results at a rate of one per minute—roughly 100 times faster than a human 'computer' of the time.