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Interpretation of Pierce Mill by the Miller,
"Or Why I Learned to Love Oliver Evans and Hate the Past."

Master Miller Ted Hazen Demonstrating One Step in the Miller's Touch.

Interpretation of Pierce Mill by the Miller,
Theodore R. Hazen,
Master miller (mill operator), Millwright,
Curator of Molinology, Site Supervisor, and Lead Interpreter,
Pierce Mill, Rock Creek Park,
National Park Service, 1985.

Milling Process and Methods of Milling at the Time of Pierce Mill Construction.

The milling process is simple, it can be divided into three steps:

1. Clean the grain of dirt and chaff.
2. Grind the grain.
3. Bolt chop to reject husks or bran.
At this time "low" or close milling was in use by American Mills. This was the role of the American mills in milling, in the 1820's. The process of "low" or "flat" milling depended upon these factors: A. Run the millstones close together, to make as much flour as possible in the first grinding. There was no regrinding to increase yields.
B. The runner stone must be careful balances, so as not to touch the bed stone, to prevent damaging the millstone dress or creating sparks.
C. The miller did not dress his millstones, they depended up the skilled millstone dressers with a proof staff and mill pick. They traveled form one mill to another dressing millstones.
D. The millers in grinding avoided making many middlings, which might have be reground to get a higher yield. Middlings are mixed with fine particles of bran and germ. The did not have a device to remove the middlings. When reground it would make a poor grade of flour. This was called "Red Dog."
E. American millers adopted the Oliver Evans system of flour milling and his improvements. The District of Columbia had at one time 56 water power mills, built mostly to grind wheat and produce white flour. The District of Columbia was originally covered by large estates rather than farm land. By 1790, all the new and existing mills had been built or converted to the Oliver Evans system of automated flour milling.
The type of wheat grown in the east at this time was "soft winter wheat" or English wheat, which makes a "whiter" flour. When ground the bran comes off, as a broader bran flake, and little middlings contended within as compared to the later hard wheats.

To sifted off waste of bran, middlings, and germ, called offals, since they were offal to get rid of and offal to get rid of. Often the offals were ran into the tail race and discarded. A chute poured the offals into the race since there was no animal feed stuffs business at this time.

In this old close grinding system of milling, the millstones had more land than furrows, it also depended upon running the millstones fast, with heavy feed, thus making hot damp meal. So the milling system needed the hopper-boy as part of their milling system.

Hard (spring) wheat, which began to be grown in the western states, has a brittle bran which makes a better bread flour, but makes more middlings, which the miller must avoid. It makes a white flour inferior to that produced by soft or winter wheat milling.

In "low" or "flat" milling, the millstones had to be well furrowed with sharp edges, so they could make a much flour as possible, in just one grinding. This is a weak system, which does not take in account the physical composition of the wheat berry.. The wheat berry has four parts: 1. The outer husk or bran, composing 5% of the whole.
2. Aleurone or gluten, composing 3 to 4 % of the whole.
3. Starchy interior or endosperm, composing 80% of the whole.
4. Embryo or germ, composing 10 to 11% of the whole.
In "low" milling the millstones grind the flour elements into an indiscriminate or meddled mass. Thus creating many problems with low milled flour. The main problems are: 1. The flour permeated with oil from the wheat germ, which becomes rancid and deteriorates quickly.
2. A portion of the bran pulverizes, so it can not be separated from the flour. Thus makes flour which is discolored and flour.
3. The bran absorbs moisture, thus causes the flour to deteriorate.
4. The glutinous mass of cells, next to the husk, the middlings are only partly disintegrated, they will, because of particle size be bolted out with the bran. This is the only plus to the system!
The winter flour bought a higher price than spring wheat flour. Winter wheat was of superior milling quality. The problems in "low milling magnified when the mills tried grinding spring wheat. Four the mills to grind spring wheat, it was necessary to run the millstones with great pressure and at a high speed, thus causing heat generated problems: 1. Discolored flour.
2. Injured keeping qualities of the flour.
3. Husk of the spring wheat, is thin and brittle, thus would crumble into fine particles, which were very difficult to sift from the flour.
The winter (sort) wheat has a thicker, tough bran, thus milled, is more likely to separate from the kernel into large flakes, more easily sifted out. The winter wheat is more easily ground with millstones.. It does not require great pressure or speed to mill it. Great pressure and speed would result in heat causing overheating and discoloration of the flour. Thus grinding was slow. Milled winter wheat is whiter, stronger and less likely to spoil. All-purope flour is milled with a blends of generally 80% soft wheat and 30% hard wheat, or at least 50-50 blend of each. Thus arose the need for tempering (moistened) the wheat, to toughen the bran.

In 1809, the first steam powered flour mill was constructed, using an Oliver Evans steam engine, in Pittsburgh, Pennsylvania. The mill was built by George Evans, Oliver's 23 year old son. This began the Oliver Evans dream of a steam powered automatic flour milling era.

Custom Milling versus Merchant Milling.

At the building of Pierce Mill, the Chesapeake Bay and Baltimore areas were the flour milling centers of milling. The custom mill, practiced custom or batch grinding. They did not buy and sell grain at all, but found their business in the toll of grains they milled. The pure custom mill was found in rural areas and a rarity in the cities of the Bay area. The custom mill usually had one pair of millstones and could not afford the installation of the Oliver Evans milling equipment. The merchant mill did not make a profit on the milling of grain. They bought the grain, milled it and made a profit or loss on the sale of the flour product. The merchant mills, such as Pierce Mill, and the Colvin Run Mill, could afford to install the Evans milling system in their mills. The Chesapeake Bay area millers sold their r flour for export and domestic trade. Pure white flour, because of Evans, became of standardized quality. It was then offered to the public for sale, at a competitive price. The Oliver Evans inventions for automatic flour milling are: 1. Process of flour making by automatic machinery.
2. The elevator.
3. The conveyor or auger.
4. The hopper-boy.
5 The drill.
6. The descender.
7. The kiln drier.
The effects of Evans Inventions on the Milling System were: 1. Oliver Evans solved the milling labor problem, before the industry became aware there was a problem.
2. labor saving to the flour industry.
3. Increase the flour mills output.
4. American mills became superior to mills in the rest of the world.
5. Increased the export trade of flour.
Large merchant mills took an advantage over the smaller mills. They had more capital to invest in the Evans improvements. Evans new machinery was costly, it required a larger amount of capital and larger amounts of power to operate the mill. More money had to be spend on mill buildings, mill dams, mill water wheels and improved mill gearing, which required a larger expenditure of capital than ever before.

The Oliver Evans automatic milling inventions created a snow ball effect in other areas. Some of the effects are: 1. The development of manufacturing, the change of industry from a handicraft to an automated industry.
2. The growth of cities centers of milling developed and grew.
3. Development of transportation, more grain and grain products needed to be transported, from the farm to the mill, from the mill to the markets.
4. Creating wider markets, increased flour production and improved quality of flour created new flour markets.
5. Large scale production, increased output with less labor involved in the milling process.
6. Larger capital mills profit increased, so the industry had more capital.
7. Localization in industry flour milling centers developed and grew in area near transportation and grain growing areas.
8. Milling centers needed to be close to the wheat supply.
9. Developments in agriculture, increase production of the flour mills. This meant agriculture could then make developments to increase grain production. If the milling industry could not mill more, why make developments to increase their production.
Some of the effects seen after Evans inventions were: The adoption of Swiss silk cloth to bolt flour, rather than wire, linen, horsehair, or woolen material. So finer white flour could be bolted. American millers about 1825, asked Dutch weavers in Harlem, New York, to begin producing an even stronger cloth. The Swiss weavers copying techniques originated in the Harlem mills, perfected the silk cloth that would become the standard into modern times. It came into use in America before it was found elsewhere. This created another reason American mills produced better flour than in other countries. Another effect was the beginnings of experimentation of millstone dress to make flour as clean as possible and increase flour yield. Thus so as not to pulverize the bran, so then it would not be difficult to bolt out of the flour. Their third effect was, improvements made to the adjustments of the millstone, in tentering. So it was possible to make finer adjustments more quickly. And lastly, new developments in grain cleaning, the separator introduced. So sticks, stones, straw and foreign material sifted out with a blast of air. Smutters to scour wheat, more effective cleaning than with the rolling screen cleaners. They removed foreign material and dirt, loose bran and the beard of wheat, etc.

With Evans ended the millwright fabrication of machinery. Evans built a company in Philadelphia, Pennsylvania. The first to commercially produce mill equipment. Evans did not put his name on the equipment, which was made. Rather than complete millwright fabrication, the millwrights began to the installation work of installing machinery.

Evans inventions effected the miller as well. It changed the work station of the miller. The controls that once where at the meal bin, now the miller moves to the first floor with his controls there. The elevator moved the miller out of the basement. Some of the problems with the pre-Oliver Evans basement mill operation were: 1. Poor light.
2. Dampness.
3. Dirt floors.
4. Miller not at his millstones.
The removal of the meal bins and basement controls, since they are pre-Evans. Some times adaption to an Evans system was made, chutes though bins to fill elevators. Rod controls to the first floor, from the bridge tree, for the first floor millstone control. The elimination of custom or batch grinding to an Evans milling system. Evans milling system, meant merchant milling. The basement then was used for maintenance and closed off. Problems with the basement, too damp, and the miller too faraway from his millstones. Cool in the summer but too cold in the winter. It also effected the miller's health by being stationed in the mill's basement all the time. The miller's helpers or apprentices worked in the upper levels of the mill.

The "low" milling process, is just a two step process. 1. Grind the wheat. 2. Bolt the flour. This type of grinding is called by later roller millers as "sudden death" or the "rotten reel" flour. It was still a positive grinding system, feather edge to feather edge. With Evans automated milling system meant, millers could adopt a new milling system, in which regrinding could be used with sifting to increase the flour yield.

An operating mill means: 1. Not running all the time. Mills do not make flour every minute they are open.
2. Down time, need time to fix things, repair, dress millstones, etc.
3. There are times when they do not need to grind grain.
4. There are times when the mills can't grind. These are periods of low water (often in the summer months). Back watering of the water wheel (during spring floods). And icing of the water wheel (often during the winter months).
The millers and millwrights have pride and workmanship. One man making one thing, by one's (him or her) self. They used hand made tools on hand made machines, this reflects the culture from which it came. It was a time when they repaired it, rather than throw it out.

The technology "process" not the product changed. Flour had improved over the years, but has still remained similar. The process had greatly changed. The mill, Pierce Mill, can make flour as good as, it not better, than modern made flour. The process has changed over the years, not the product. And at Pierce Mill, we are interpreting the technology process, by which it is made.

Some of the Problems with the pre-Evans Milling are: 1. Problems of over speeding. No other machinery to take over loads. A greater chance of runaway. Before Evans, only the millstones were water powered.
2. Too much labor involved in the milling process. A system of separate, individual steps, Evans connected the steps into one process, of automated milling.
3. Too increase output, needed to increase labor, and machines. The present labor and machines could not produce more. A human and hand operated milling system, needed a new system to increase production.
4. Machines (bolters, cleaners), designed for hand feed, problems of over feeding resulting in poor flour (product), not constant in quality of product.
5. The miller and the millstones controls in the mill's basement. The miller needs to be with his millstones to effectively run the mill. The mill's basement was too damp and cold in the summer and winter. There was poor light in the basement. The first floor only used to fill millstone hoppers and to dress the millstones. This meant mill was operated and the business conducted in the basement. The miller and his customers are exposed to dampness and cold. Records and paper also suffer, along with the product.
6. Material too easily contaminated and exposed to dirt. People did not think twice about walking across piles of flour aging on the floors with road dirt on their boots. Or jump into a barrel of flour to compress it with muddy boots. People did not like eating dirt but they felt they could do nothing about it.
7. The mill building not related to the interior machinery. Form did not follow function. A mill building could look like any other building in an area with the exception of a water wheel attached
8. Limited output of product and input of raw material.
9. Great amounts of spillage and loss in physical movement of material.
10. Bolting often a separate process, taken to a bolting mill, separate from the mill. Sometimes the baker was the only place were flour could be bolted. This meant that another toll would be taken!
11. The water wheel and mill gearing of limited power design. To increase power for another millstone or additional machinery another water wheel had to be added. The state of the art of pre-Evans mill gearing could not operate the additional machinery that came with an Oliver Evans automated flour milling system. New forms of mill gearing had to develop and be used, such as great spur gear drive.
12. Total milling time, long, greatly shorten by the Oliver Evans system. Long milling time, meant long time the material is exposed to insect infestation. Evans system greatly reduced the milling time so there was less possible insect infestation.
13. Milling system could not keep up with new developments in farming, so why should farming make any advancements, if milling could not keep up with the increase in production. Mills advanced technologically first to allow farming to catch up. With an Oliver Evans system, a mill could grind three times as much grain with a fraction of the labor involvement.
14. Small custom mills and large merchant mills used the same system of operation and the same throughout the world.
15. Millers saw nothing wrong with their system and were reluctant to accept change to their system.
Interpretation Oliver Evans Program: Bibliography.

Steven Kindig, "Oliver Evans," a T.I.M.S (The International Milinological Society) paper, no date.

Steven Kindig, "Oliver Evans," a lecture, the second Mill Symposium, Colvin Run Mill, Great Falls, Virginia, 1985.

Terry G. Sharrer, "Oliver Evans, and the Beginning of Automated Milling in Maryland and the Upper South, 1783-1812," Eno, Volume 7 Special Issue,1978. Papers from the semimar on water mills & windmills held in Durham, N.C. July 1978, in the Bicentnnial year of West Point on the Eno River, with The International Milinological Society (T.I.M.S.), Smithsonian Institution, Duke University and the Hillsborough Historical Society, pages 11-24.

Now Look at the Same Basic Program,
Toned Down and Tweaked a Bit to Appeal to a Wider Audience,
and to Fit more into the Main Theme of the Site.
Oliver Evans and Peirce Mill,
"The Unofficial Oliver Evans' National Historic Site."

Grinding other Grains: The meal box sifter most often was used for these types of grains.

Master Miller Ted Hazen Demonstrating Bagging of Cloth Flour Sacks.

1. Corn, field corn used to grind into corn meal. A corn mill which had one millstone and ground just ground corn, often called a "corn cracker." There is a regional differences to the milling of corn.White corn is milled in the South, while yellow corn is milling in the North. In central and eastern Pennsylvania, they mill roasted corn into meal. Corn is the poorest in nutritional of the cereal grains. It has no export value. In Europe corn is mainly used for animal feeds and is almost unknown as a human food product. Corn is the English word for grain, mainly wheat, rye, oats, or barley. When talk of our corn they call it maze. In England, a corn mill would grind anything but what we call corn or maze. Corn contains no explosive dust. Products from the milling of corn are: 1. Corn meal (bolted and unbolted). 2. Corn flour (bolted). 3. Corn grits (cereal). 4. Corn bran (used mainly for animal feeds).

2. Buckwheat, is not a cereal grain, it is a flowering herb, used as a cereal grain. Buckwheat in German is "buckweizen" meaning "beech wheat" because of its similarity in appearance to beech nuts. A three sided seed. Buckwheat originated in central Asia, spread to China and Japan. Then it was taken to Europe in the middle ages. The Dutch and German settlers brought it to New Amsterdam (America) in 1626. Buckwheat is call by the farmers, "the poor man's crop" because sometimes its yield is not as much as they planted. It will grow on rocky and poor soils where other crops will not grow. Buckwheat is nutritionally superior to the other cereal grains. It is natures highest source of natural protein in the plant kingdom. It does not contain gluten for those allergic to wheat. Buckwheat also is sold in Eastern Europe as Kasha, which is roasted buckwheat groats. Buckwheat contains no explosive dust but it is very dust when milled. The bolting of buckwheat requires finer screens than that are used for making whole wheat flour. The products of buckwheat are: 1. Buckwheat flour (bolted). 2. Buckwheat cereal or middlings. 3. Buckwheat hulls (a non-digestable food stuff).

3. Rye, a hardy annual, is widely grown for grain and as a cover crop. Rye is most often used in bread making and rye whiskey. Rye has a problem with the fungus ergot which is similar to the chemical composition of LSD. It is not effected by the milling or the baking process. Rye is also used in making pumpernickel breads. The products of rye are" 1. Rye flour and whole rye flour (bolted). 2. Rye meal and pumpernickel flour (bolted). 3. Rye bran.

4. Barley, a cereal grain is used in malt beverages, in breakfast foods and soups. Barley is often sold as "pearled" barley which means that the bran is rubbed off. The products of barley are: 1. Barley flour (bolted). 2. Barley cereal.

4. Oats, a cereal grain, which a reed instruments are made from oat straw. Oats can be ground into flour but it is mainly used as a porridge (meal made from oats) made from millstone ground or rolled oats. Rolled oats, a new process milled on smooth roller mills, and quick oats is rolled oats ran through a roller mill cutting the oats into three to five pieces, thus reducing the cooking time. Oats have problems with moisture in the storage and milling of its products. Oats are covered in a hull, which is totally non eatable. To remove the oat hull, often the oats are roasted in a kiln to crack open the hull, then it is run through a pair of hulling stones to separate the hulls from the oats. The millers knew for years that oat bran was good for people before it was discovered by nutritionalist. Some products made form oats are: 1. Oat flour (bolted). 2. Oat meal (millstone and roller milled). 3. Oat bran.

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Copyright 2002 by T.R. Hazen.