page_title: Oliver Evans
section_title: Developing the automatic flour mill, 1783–90
hierarchical_section_title: Oliver Evans / Developing the automatic flour mill, 1783–90
caption_attribution_description: English: From U of Delaware Postcard archives, from an 1840 painting by Bass Otis who died in 1861.
context_page_description: Oliver Evans was an American inventor, engineer and businessman born in rural Delaware and later rooted commercially in Philadelphia. He was one of the first Americans building steam engines and an advocate of high pressure steam. A pioneer in the fields of automation, materials handling and steam power, Evans was one of the most prolific and influential inventors in the early years of the United States. He left behind a long series of accomplishments, most notably designing and building the first fully automated industrial process, the first high-pressure steam engine, and the first amphibious vehicle and American automobile.
  Born in Newport, Delaware, Evans received little formal education and in his mid-teens was apprenticed to a wheelwright. Going into business with his brothers, he worked for over a decade designing, building and perfecting an automated mill with devices such as bucket chains and conveyor belts. In doing so Evans designed a continuous process of manufacturing that required no human labor. This novel concept would prove critical to the Industrial Revolution and the development of mass production.
context_section_description: Evans's attention turned to flour milling in the early 1780s, an industry which was booming in rapidly industrializing northern Delaware. In this era, the operation of grist mills was labor-intensive. Although the stages of the milling process—grinding, cooling, sifting and packing—were beginning to be mechanized to various degrees, gravity or manual labor was required to move grain from one stage to the next. Additionally, some stages (particularly cooling) were slow and inefficient, creating significant production process bottlenecks. Mills were becoming commonplace in populated areas and those with ready access to waterways for power, but the bulk of milling in the 1780s was done in the home through hand milling. Furthermore, the quality of milled wheat was poor in colonial America. Hard wheat varieties were insufficiently ground and sifted by mills, leaving a flour that was coarse and brown. Cross-contamination was a major problem: mill processes were not well-partitioned; the many people moving about the mill contaminated the flour with dirt, grain and other impurities.  The end result, Evans recognized, was a low quality product that took too many laborers to make.
  In 1783, two of Evans's brothers began building a mill in Newport on part of the family's farm estate which they purchased from their father, and Evans was recruited to oversee its construction on the Red Clay Creek. When the mill opened in 1785 it was of a conventional design, but over the next five years Evans began to experiment with inventions to reduce the reliance upon labor for milling. Moving wheat from the bottom to the top of the mill to begin the process was the most onerous task of all in contemporary mills. Evans's first innovation was a bucket elevator to facilitate this process. Chains of buckets to raise water was a Roman technology had been used in various guises since antiquity. Evans had seen diagrams of their use for marine applications and realized with some modification and careful engineering they could be used to raise grain, so a series of bucket elevators around a mill could move grain and flour from one process to the next. Another labor-intensive task was that of spreading meal. This came out of the grinding process warm and moist, needing cooling and drying before it could be sifted and packed. Traditionally the task was done by manually shoveling meal across large floors. In response, Evans developed the "hopper boy", a device which gathered meal from a bucket elevator and spread it evenly over the drying floor—a mechanical rake would revolve around the floorspace.  This would even out newly deposited meal for cooling and drying, while a gentle incline in the design of the rake blades would slowly move the flour towards central chutes, from which the material would be sifted. Used in conjunction, the two innovations saved many hours of labor and greatly reduced the risk of contamination.
  Despite their technical complexity, neither device was revolutionary by the standards of the time. However, the total vision of their design was. Evans was attempting a radical shift in thinking about the manufacturing process, treating it as a continuous integrated whole rather than a series of isolated processes. Thus, manufacturing could be a fully automated production line. The missing link was materials handling, and Evans's mill designs sought to feed materials continuously through a system without the need for any human intervention. This was the first fully automated industrial process, and the idea of continuous production was proved to be a critical ingredient of the industrial revolution, and would ultimately lay the foundation for modern mass production.
  Constructing the machinery to realize this vision was complicated. Evans struggled to find the money to pay the highly skilled carpenters needed to construct his complex machines. The nearby flour milling industry on the Brandywine River was large, but dominated by the Quaker millers of Wilmington who saw little potential in Evans's designs. James Latimer, a Newport flour merchan
caption: The Brandywine Village became an influential early adopter of Evans's milling processes.
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