You never know which obnoxious thing will become a hit 100 years later. In the days before elevators, penthouse-level apartments were the cheapest and least desirable. Lobster was so over-abundant in colonial New England that it was rejected by all but the imprisoned and the destitute. And treadmills, which today account for about $1.4 billion a year in North American retail sales, were invented as a form of prison torture.
It was called the Discipline Mill—or “tread-wheel,” according to Sir William Cubitt, the English engineer who invented the predecessor to the modern treadmill in 1818 as a means to occupy prisoners sentenced to hard labor. You can still read an 1822 description of it and shudder with familiarity. Ten to twenty prisoners stood upon a long wooden wheel affixed with 24 “tread boards” around its circumference. Gripping a horizontal bar for support, the prisoners stepped in unison, pushing the wheel around in exactly the manner a river moves a water wheel. While the wheel was mainly used as a form of punishment, one infamous wheel at Brixton Prison was used to crush grain, giving the device its lasting name, the treadmill.
While even an hour on today’s treadmills can be a monotonous challenge, 19th century inmates faced the herculean task of powering the Discipline Mill for six or more hours a day. According to one 1822 report, “the diameter of the wheel being five feet, and revolving twice in a minute, the space stepped over by each man is 2193 feet, or 731 yards per hour.” Were the prisoners wearing Fitbits, that afternoon of cardio would clock in at anywhere from 13,000 to 18,000 consecutive steps.
The tread-wheel eventually fell out of fashion as a punishment toward the late 1800s when American prisons turned to similarly backbreaking labor like picking cotton or smashing rocks, and British prisons abandoned the wheel for being too evil. What was once a form of torture became a leisure activity by the mid-1900s, when a rise in factory and office jobs led to an increasingly sedentary population. Treadmills, now looking more like factory conveyor belts, were suddenly revived as luxury items for laborers who spent all day sitting.
Today you can pay upwards of $1,000 for the pleasure of owning a machine that one English historian calls “the harshest form of punishment, short of the death penalty, for about 100 years.” But, hey—at least you get to choose when to step off.