First the wheat must be cleaned. This is done by shaking the wheat over a screen that is only large enough to let the wheat pass through. The next step is to scrub the wheat. The wheat is transferred via elevators into a smut machine that scrubs off the fuzzy exterior of the grain. The remaining dust and dirt is removed from the wheat in a winnowing machine that pulls out the waste residue. Once the wheat is cleaned, it is stored in a hopper until the miller is ready to grind it.
When the miller is ready to grind the wheat it is transferred to the millstones via a series of elevators and shafts. Once the wheat is run through the stones the powdered flour is lifted to upper floors where it is sifted through bolting cloths often made of silk. Flour that is bolted (sifted) through the finest cloths (silk) was the best quality produced. Before sifters were available in mills, pioneers would take the flour immediately after it had been ground and sift it at home. It is necessary to sift the flour in order to remove the bran.
If a mill was to solely grind corn for cornmeal then there was no need to have more than one level in the mill. If, however, the mill was to be a multi-purpose mill, which most mills were, that is to grind cornmeal and wheat for flour, then it was necessary for the mill to have at least three levels. Cleaning, scrubbing, storing grain, grinding, sifting and storing the bagged flour required a multi-level complex to accomplish the various stages of processing wheat into flour. Each mill would be built to suit the demand that the miller thought would satisfy and serve his customers. Storage was a major consideration. If the farmers needed the mill to hold large quantities of grain, the miller had to accommodate that demand by building storage bins and hoppers.
Overshot Waterwheels in Ohio
The overshot waterwheel has a face. The face is the width of the buckets. The wooden troughs are the buckets. When the water fills the buckets, the water's weight moves the wheel. An overshot waterwheel receives its water above the wheel. An overshot waterwheel is the most efficient method of powering a mill when there is a limited amount of water supply because the overshot produces the greatest amount of head for the water to turn the wheel. Head is the force that the water has when it drops vertically from the millrace onto the wheel to the tailrace. The greater the distance is between the headrace and the tailrace, the greater the head. The overshot waterwheel was used when there was a dependable flow of water but when there wasn't a high rate of flow. The overshot waterwheel maximized the amount of accessible water-power.
The location of the mill determined whether a millrace was necessary. A millrace, also known as a headrace, was the channel that directed water from the stream to the waterwheel. The millrace was often several miles long. The reason the race would have to be so long was to build up the head of water so that the drop would produce enough power to move the wheel. The millrace would begin upstream and if the drop was significant over a short distance, it wasn't necessary to have a long millrace. If the land was relatively flat, the miller had to dig a millrace that was miles long. Often there wasn't an easy way to transfer the water from the millrace to the waterwheel and a wooden flume had to be built to make the final connection.
Once the water flows into the buckets and moves the wheel, the water is spent and must then be channeled back to the stream. The channel that it flows back to the stream in is called a tailrace. Usually the tailrace is not very long. It usually takes the shortest route back to the stream.
Turbines
The turbine was introduced in the late 1890's. It operates on a similar principle as the tub wheel. The turbine is made of iron and the wooden round tub is replaced with iron and is composed of numerous doors on hinges that allows the miller to open the doors at varying degrees allowing as much water as he wants to pass through the turbine. The more water he releases into the turbine the faster the shaft will turn. The less water he releases into the turbine the slower the shaft will turn. With the advent of the turbine, many mills switched from wooden waterwheels to the iron turbines. Wooden waterwheels consistently had to be repaired. Rotten wood had to be replaced and the wooden wheel always had to be maintained in order for it to keep its balance. When the waterwheel became unbalanced the waterwheel would shake and the mill building would vibrate. The turbine required virtually no maintenance. Grease would have to be applied to the hinges every 2 or 3 years but otherwise, the turbine would last for 60 to 70 years before it would rust through and have to be replaced. The turbine also was an excellent conductor for energy, transposing it from the water flow to the power train. The water turbine was efficient and powerful. Consequently, the turbine experienced a positive response from millers throughout the United States.
ADDITIONAL TYPE OF WATERWHEELS
Breast Waterwheel
The breast waterwheel uses the same design as the overshot waterwheel with the buckets. The water hits the waterwheel in the middle, propelling the wheel down. The water can be directed to hit high, middle or low on the waterwheel and still be classified as a breast waterwheel. This type of wheel was used when the flow of water wasn't swift enough to power an undershot wheel but the flow had enough velocity so that an overshot was not required. The overshot waterwheel and the breast waterwheel were often located in a wheel pit. The wheel pit is an enclosure for the wheel that was lined with stone.
Undershot Waterwheel
An undershot waterwheel was placed in such a manner so that when the headgate was open, the water flowed under the waterwheel propelling it to turn from the movement of the water striking three to four of the paddles at a time on the wheel. The undershot waterwheel was constructed with blades instead of buckets. Headgate is a term used for the gate that opened and closed allowing the water from the millrace to flow to the waterwheel. The headgate is also known as the sluice gate. What was referred to earlier as the wooden flume is also known as the sluice. This type of waterwheel could only be used where the flow of water was extremely high. It takes a great deal of velocity to turn a large wooden waterwheel. The undershot waterwheel was not as popular as the overshot but was used wherever there was an ample water supply and a rapid flow.
Flutter Wheel
The flutter wheel was a much smaller waterwheel. It functions just like the undershot waterwheel. It has seven or eight blades attached to the shaft and the water flows under the flutter wheel rapidly. This type of waterwheel was used in a stream or millrace that had an extremely high rate of flow and the wheel would turn rapidly. The flutter wheel was not a substantial type of wheel and therefore required consistent maintenance and had to be replaced often.
Tub Wheel
The tub wheel was another type of waterwheel. Like the flutter wheel and undershot waterwheel it had blades rather than buckets but its blades were attached to a vertical shaft at a 30° angle and was enclosed by a wooden round tub. The water would drop down on the blades forcing the blades to turn the vertical shaft. This type of waterwheel was often used in high velocity mountain streams.
One variable that distinguishes each mill is its power source. In the early 1800's all of the mills in Indiana were powered with water and wooden waterwheels were used to turn the buhrstones. Although each mill used water to power their mills, the individual design for each mill had to reflect the position of the waterwheel relative to the stones. If the waterwheel's shaft was on the same level as the stones, there was no need to transfer the energy via gears, pinions, belts and pulleys to an elevated level. If, however, which was often the case, the waterwheel was positioned lower than the mill building itself, or if the waterwheel was located in the lower level, then the energy had to be transferred up to the level where the stones were located.
Usually the buhrstones were located on the entrance level solely because the weight of the stones prohibited the miller from carrying them up even one level. The stones could weigh as much as 2000 pounds each! The normal configuration of a mill would be where the wheel was located outside on the lowest level of the building (basement) and the stones would be located on the first level of the building (entrance level).
If the mill was designed as a flour mill, there would be at least two additional levels above the first floor. The flour mill would be filled with elevators and shafts that traveled from hoppers to scrubbers back to hoppers to elevators that accessed the stones. Once ground, the flour would be elevated to high levels so that it could go through various sifting stages and sorted by different grade levels.
Many old mill buildings are found precariously built on the edge of a river with the dam right at the mill sight. Other mills are located at an elevated level above the river to avoid spring floods. The mill site itself is often much older than the present structures that we find today. Early pioneers were skilled in identifying a successful location for mills. Initially, the pioneer would build a temporary mill where he would construct a sawmill. With the sawmill he would mill wood for the gristmill and the miller's house. Once the gristmill was completed, the sawmill would often be discarded because it was built for the short term. The gristmill would be placed in the optimal location relative to water-power and out of the yearly flood plain. The old sawmill would be transferred to an exterior shed on the new mill or discarded. The gristmills that were built in the early 1800's were small and only ground corn and wheat. Bolting flour in the mill was not accomplished until the population increased to the point where it was economically feasible for the miller to construct a multi-level building and invest in bolting equipment. Once the community grew large enough to support a flour mill, the gristmill was renovated or dismantled and replaced with a new multi-level flour mill. There are a few old flour mills left today that were built in the 1840's and 1850's. The reason that there are so few remaining is that the process of cleaning wheat, grinding wheat, and sifting flour created a combustible dust. Although the millers would clean their equipment and constantly remove the buildup of dust, explosions would often occur. The dust would start to decompose and produce enough heat where it would burst into flames. The old mill buildings were built solely of dry wood and they would ignite like a pile of dry kindling. Poof! The mill was gone. Consequently, many old mills were destroyed by fire. These multi-level flour mills that were built in the 1840's and 1850's usually burned within 10 to 20 years and then they were replaced with the buildings that remain today. This explains why most of the old flourmills that we see today, even the old ones, were built in the 1880's and 1890's. Many mills still burned in the late 1800's. It is just that the technology increased and the equipment that was installed in the latter 19th century was more refined. When adequately maintained the accumulation of flour dust did not occur.
The mill sites in the early 1800's were established to serve local farmers. Transportation of farm crops did not become feasible until the advent of the railroad. Early mills were designed specifically to serve the local communities. Before the number of mills proliferated, it was not unusual for farmers to travel a day or two to take their grains to the nearest mill.
The mill was the hub of the community. It was the place where the local farmers would meet and discuss current affairs and socialize. The miller was recognized as a pillar in the community and his thoughts and ideas were respected. Because the mill became the focal point of the pioneer communities and because the mill was always located on a river, access to the mill was of great importance. Even when the rivers were swollen, the farmers still needed to have their grains processed so one of the first things that the community would allocate tax money for was the construction of a bridge at the mill. The combination of covered bridges and mills were a common sight in the late 1800's and the first half of the 20th century. Even with the flooded streams, the covered bridges allowed passage across the swollen rivers. When the mill sites were initially developed there were no neighbors, schools or stores around. Once a success, the mill became the nucleus of a new community. Trading and barter would be done at the mill. News and stories were shared there. Eventually other trades would build shops and stores would open near the mill because the mill was central to the community.
A skilled miller would look at a prospective mill site and determine what type of waterwheel would function best given the variables such as supply of water, rate of flow and physical location of the mill.
If the water propelled the wheel too fast it would burn the stones and equipment in the mill and eventually wreck the wheel. This happened once in a while when the sluice gate broke and the flow of water to the penstock was not controlled. The penstock is the area where the water is held immediately prior to the waterwheel. When the waterwheel would spin out of control the entire mill would start to shake and rattle. The stones would start to smoke, spinning so fast the stone would scar and all of the machines that were connected to the shaft at the time of accident would be at risk. The miller would immediately disengage the gears so that the wheel could not propel the power shaft.
Often the waterwheel's shaft was not able to access the stones at the same level so the energy had to be transferred up at least one level. The waterwheel has a shaft that extends from the center of the wheel out to another wheel that has numerous teeth. The wheel with the teeth is called a crown wheel. This crown wheel turns and the teeth mesh with a cylinder that has round gears in it. This cylinder is called a lantern pinion. It is turned by the teeth in the crown wheel and transfers the energy up through a power train that is comprised of additional gears, shafts, pulleys and belts. The diameter of the lantern pinion is only one-fourth the diameter of the crown wheel. Subsequently, the lantern pinion moved 400% faster. Through transferring energy from larger to smaller gears, the millstones turned over 100 times each minute. Consequently, when the waterwheel would make one revolution each minute, the millstones would spin 100 times during that same minute.
Millponds were created as a result of damming up a stream. Dams were made of rock or wood. The rock dams ranged from a rubble construction to a wall of beautifully layered cut stone. The wooden dam construction ranged from brush to huge squared timbers. Once the dam was constructed with hand-hewn timbers, the back of the dam would be filled with brush or rubble and silt would eventually fill in and secure the dam's construction. When the dam would become eroded and a break would occur, the miller would lose business until the dam could be restored. When the dam broke it was a serious situation financially for the miller and it created a hardship for the community.
Behind the dam the waters would rise and often flood acres of land for many miles upstream. In the early pioneer days, farmers were grateful for the presence of the mill to grind their grains and didn't complain too much when the rising water consumed some of their land. However, with the increase in the settlement of the territories, there was always some dispute arising from the establishment of a new mill. When the dam was built it would often flood a farmer's field. Needless to say, that farmer was not too happy about the situation and the local town government often had to step in and settle the issue. Usually the town government ruled in favor of the mill because the community's need for the flourmill and gristmill far exceeded the loss of land to a few farmers. Water rights became an important issue to owners of mills and to the prospective buyers of established mills.
The water pool that forms above the dam is called the millpond. It is this supply of water that allows the mill to continue functioning during periods of low rainfall. The millpond is usually a distance upstream from the mill. A millrace is dug channeling the water from the millpond to the waterwheel. If a millrace is not acceptable, a wooden water flume is constructed to carry the water over valleys or areas where the height of the land is not able to sustain the head of water necessary to power the waterwheel.
Gates are constructed where the water from the pond enters into the millrace. These gates are called headgates or sluice gates. These gates are opened and closed according to the demand of water needed by the miller. Often there are gates built in the millrace just before the water spills onto the waterwheel. These gates are also called sluice gates and this area is often referred to as the penstock. In the penstock area it is possible for the miller to divert the water from the flowing millrace past the waterwheel back to the stream. The miller redirects the water flow with gates in the penstock and the water simply enters the tailrace without passing over or under the waterwheel or turbine. The gates in the penstock are used by the miller when he does not need the water supply because he doesn't have any grain to process and he does not want to run up and close the sluice gates at the millpond only to have to go back and open them when the water supply is needed.
If I was struck by any one thing that I found consistently at each mill site, it was the inconsistency of design. I have been to approximately 500 mills and I can tell you unequivocally that there are no two mills alike. There is a fundamental reason why each mill is independently different from any other mill. When the miller identified a location for his mill, he had to take into account the location of the stream relative to the prospective mill site. The miller had to design the millrace and how it would connect with the waterwheel. He had to account for the geology of the immediate area. The miller has to assess the distance and fall of the stream so that the head of water would be sufficient to turn the waterwheel. There are more than a few mills in the United States that have a millrace that exceeds a two mile distance because the surrounding land was so flat that in order for the miller to get the head necessary to move the waterwheel the water had to travel a greater distance. Many sites in the United States, the miller built the mill at a natural waterfall and there was no need for a millrace. He simply channeled the water into and through the mill or he built a short wooden flume to direct the water at the exterior waterwheel which was constructed at the dam. The design of each mill was dictated by the accessibility of water-power.
Each mill was built of different materials. If stone was available and if there was someone who had the masonry skills to build the mills with stone, it was done. Stone mills were an expensive method of construction but the stone mills that remain are spectacular. Most often, the miller, the one who owned and operated the mill, was the person who constructed the mill. Consequently, the mill's construction represented the miller and he took great pride when designing and building the mill. The miller was a respected member of the community and the pride that he took in constructing his mill can still be witnessed today. Whatever skills the miller possessed, whether it be masonry, crafting huge logs into hand-hewn timbers for trusses in the mills, or creating ornate trimming, each mill that remains stands as a monument to the miller who initially secured the site for the mill and constructed the building that housed his business for many decades.
There were no rules on how to build a mill. Being a miller was a trade. Young boys would apprentice to a miller for as many as 10 years before they would learn all of the skills necessary to function as a miller. He would not only have to know how to build the physical mill building itself, but he would have to know how to build and maintain all of the machinery that would fill the structure. As there were no rules on how to build a mill, there were also no "official rules" on how to construct the machinery within the mill. But there were some constants that each miller had to anticipate. First the miller had to know how to identify a site that would be acceptable to powering a mill. Second the miller had to be able to construct a sound building that would be able to access the harnessed water-power. Third, the miller had to be mechanically inclined. A miller had to be a skilled individual. He had to understand geometry, tooling, and be gifted with an instinct so that just by listening to his mill operate he could tell if any of the gears, pulleys, or shafts was malfunctioning. A talented, skilled professional, the miller would design his mill to meet the demand of the community to accommodate their needs for grinding and storing their grain. He would have to design his mill for the site requirements (water-power, floods, and access). And finally he would design his mill to reflect him personally and it was this variable that makes each mill singularly unique. I loved discovering what made each of the historic old mills special.
Old millstones are no longer a common site at a mill. Once the old stone had seen its useful days, it would be placed outside the mill for decoration. Sometimes the millers would place the millstone in the ground and they would act as part of a sidewalk. You can find millstones partially submerged in stream beds. Once a millstone was spent, it was no longer of any use to the miller and it was discarded in one way or another.
The first millstones used in the United States were in the windmills and early gristmills on the eastern seaboard. The millers who settled in Massachusetts and New York imported these stones. The millers brought the stones with them when they came to this country with the intention of building a mill and using them to grind grain. These stones were often from France and that is where the term French buhr came from. It was a granite quarry in La Ferte-sous-Fauarre in France that the finest millstones were quarried. The granite from this quarry was extremely hard. This is why it made such high quality millstones. The few photographs that have been taken of the true French buhr stones show the stone's color as white. During the late 1700's and the early 1800's the French buhr stones were imported to the United States from France and carried here in ships as ballast.
The quarry in La Ferte-sous-Fauarre was depleted by the middle 1800's. The true French buhr stones were in great demand by millers in the United States but they were very expensive. Because of the high demand for such quality stone and because the true French buhr millstones were so expensive, a miller devised a method of using fragments of the granite stone and banded them together to create millstones. This served many purposes. While mining and preparing the true French buhr stones at La Ferte-sous-Fauarre, fragments of the quality granite were discarded at the site as useless. Once this banding method became known in France, the quarry started shipping just the fragments over in the ships as ballast. These fragments and the banding method allowed millers who could not afford the true French buhrs the ability to buy stones that still offered the superior quality of the granite from France.
To obtain millstones in Ohio, millers would often cart stones for hundreds of miles to their mill. Consequently, the demand was high for millstones and a number of quarries opened in Pennsylvania and a few in Ohio, which helped supply the stones locally.
"Dependence upon imported French buhrs and buhrs from Pennsylvania quarries was eased somewhat about 1805 at least for millers in southern and western Ohio when a man named Musselman, in present Vinton County, discovered granite of excellent quality and in ample quantity to justify the manufacture of buhrstones. Because the quarry was located near Raccoon Creek, the millstones were called Raccoon buhrs. For many years this was an active industry; by 1822 the quarry employed fourteen men and two women shaping the buhrs." (Garber, D. W. Waterwheels and Millstones: A History of Ohio Gristmills and Milling. Page 78).
Millstones made of granite were the superior stone to mill wheat and corn and the only kind of stone used for the milling of grains for human consumption. Sandstone millstones were used to grind grains for animal feed. The sandstone could not be used for human consumption because during the grinding process the sandstone would disintegrate and be ground into the grain. Because the sandstone stones were ground away during the process, there are few examples of these old millstones left today.
(Adams, Erickson, Garber, Neagley, Nicosia, Page).