Oliver Evans

The two most important inventors of the late 18th and early 19th centuries were probably Eli Whitney and Oliver Evans. While Whitney is well known for his work with the cotton gin and firearms, Evans’s contributions to factory automation, the steam engine, and steam-powered transportation are all but forgotten. In fact, Evans designed the first continuous production line, built the first high-pressure steam engine, and invented the first self-propelled land vehicle in the United States.

Evans was born on September 13, 1755, in Newport, Delaware. His father, Charles, was a shoemaker, and his mother, Ann, was a homemaker. At age 15 he was apprenticed to a wheelwright, and he worked at that profession for the next six years. In his spare time, he tinkered with various mechanical innovations. His most successful invention during this period was a machine for making cards, comblike devices used to prepare the fibers of raw wool or cotton for spinning into yarn. He also began thinking about how to use steam for various commercial purposes. In 1783 he asked the Pennsylvania legislature to grant him a patent for a steam-powered wagon, but he had no working model and so his request was refused.

By 1783 Evans had moved to Tuckahoe, Maryland, where he and a brother ran a small store. That same year he married Sarah Tomlinson with whom he had seven children. He also began tinkering with ways to automate the grinding of grain into flour. Although grindstones had been powered by water, wind, and animals for centuries, the rest of the flour-making operations, such as carrying grain and raking flour, were done by hand. By 1785 he had perfected a mechanical system for performing all these tasks at a water-powered mill. The machinery was powered by the waterwheel that turned the grindstones via a system of shafts, gears, and leather belts. The operator merely dumped the grain into a hopper and engaged the clutch, thus setting the system in motion. An “elevator,” a leather belt with leather cups, carried the grain up to a “conveyor,” a screwlike rod, which positioned the grain between the grindstones. The ground flour was carried by a chute to a hopper in the drying room, where a “hopper-boy,” a mechanized rake that swept around in a circular motion, sifted the flour so it could dry more evenly. Once it was dried, the flour was bagged by hand.

In 1785 Evans and two brothers opened an automated flour mill on Red Clay Creek in Delaware, not far from Philadelphia. The operation was a financial success because it cut the cost of making flour by almost half. Over the next three years he obtained patents from four states and sold his interest in the store because he expected to make a fortune licensing his system to other millers. They, however, showed little enthusiasm for adopting his system, partly because of the initial expense involved and partly because it meant throwing people, in many cases family members, out of work. Most of those who did adopt his methods refrained from paying him a licensing fee, even though by 1790 he held a federal patent.

Evans’s experience with the automated flour mill was similar to Whitney’s experience with the cotton
gin, in that he spent most of the money he made from licensing fees on legal fees suing patent
infringers. In 1792 Evans sold his interest in the Red Clay Creek mill and opened a store in Philadelphia. He also built a machine shop and returned to tinkering with his earlier idea about steampowered transportation. By 1801 he had built a stationary steam engine, which he used to power a rotary crusher for making lime. He started by designing a direct, high-pressure steam engine with
a cylindrical boiler (the first built in the United States) rather than a condenser-equipped model of the type invented by James Watt. Then he connected the steam cylinder to the crankshaft by means of an innovative straight-line linkage, thus permitting the entire mechanism to work more efficiently. Soon he had connected steam engines to machinery for doing everything from sowing seed to sawing wood. By 1804 he had devised a way to use his steam engine to power a wagon for hauling freight over long distances, but the authorities refused to grant him permission to operate it on the Pennsylvania Turnpike because they were afraid it would frighten horses. In 1805 he invented the Orukter Amphibolos, a Greek term that means Amphibious Digger. Orukter Amphibolos was a 30- foot steam-powered barge he built under contract to the city of Philadelphia for dredging the city’s waterfront. The dredging mechanism was an elevatortype device similar to the one he had designed for his flour mill. He also outfitted Orukter Amphibolos with wheels so that it could operate on land as well as in the water, thus making it the first self-propelled vehicle to operate on land in the United States. In 1806 Evans constructed a factory in Philadelphia for manufacturing steam engines. Called the Mars Works, it included an iron foundry and a machine shop. Over the next 13 years it turned out more than 100 steam engines and boilers, as well as a host of mill machinery and other mechanical devices. Many of his steam engines provided the motive power for steamboats plying the nation’s great rivers.

In 1819 the Mars Works burned to the ground, the fire destroying virtually all of Evans’s patterns and molds. Four days later, on April 15, 1819, Oliver Evans died in New York City while on a business trip.