Types of Mills

Textile Mill

The power created by the waterwheels is delivered to the machinery by gears and belts. To run properly, machines must have their power at the right speed and direction. The waterwheel does not necessarily turn at the same speed and same direction as the machinery, so gears are used to adjust the speed and direction.

The water flows into the tub, turning the wheel. The wheel turns the shafts and gears connected to it. Leather belts connect the shafts and the machinery to provide the power to run the machine.

 

Sawmill

Sawmills were the most common kind of mills found in most 19th-century New England towns. America boasted over 31,000 sawmills by 1840. Most were owned and operated by farmers of above-average means, who often ran them seasonally, as water levels and the demands of their farm work permitted. Some cut lumber for sale, and those near cheap water transportation could ship their products to distant markets. Most sawmills, however, served neighborhoods due to the expense of transporting high-weight but low-value lumber any great distance over land. They charged local farmers by the board foot (a volumetric measurement one foot by one foot by one inch) to saw logs brought to the mill into boards, planks, and timbers. In a day one man with a sawmill could cut as much lumber as two men working by hand could do in a week.

From the 13th century until about the middle of the 19th, most sawmills consisted of a straight saw blade strung tight in a rectangular wooden frame, called a sash or gate. The saw sash is connected to a water wheel below it through a crank and by a wooden sweep or pitman arm (the latter taking its name from the man who, before sawmills made him obsolete, stood in a pit below a log and pulled a saw through the wood by hand to make boards). The turning motion of the water wheel is converted to the up and down motion of the saw by the eccentric crank. Some power from the saw sash is used to turn a large gear, called a rag wheel. This in turn moves the carriage which the log rests on, pulling the log through the saw. The saw cuts into the log on its down stroke, and the log moves forward again on the up stroke. After one board is sawed, the log carriage is run back to the other end of the mill, the log moved over, and another board cut. This process is repeated until the whole log has been sawed into lumber. Often a sawyer will square up two sides of a log first, then turn the log 90 degrees so that the flat sides are on the top and bottom. Then when he saws the log into boards they will all have straight edges. See design plans.

Gristmill

Grist is grain, and grist mills of this same basic design have used water power to grind grains into meal for baking bread since at least the first century B.C. By 1840 the United States had over 23,000 grain mills. While some were commercial flour mills milling and sifting flour for distant markets, most were neighborhood grist mills, selling the service of grinding to nearby farmers. The customer paid a toll, or fraction of the grain he brought to the mill, in exchange for having his corn, rye, or wheat ground into meal. (In most of New England this toll was 1/16th of the grain.) The owners of early 19th-century New England grist mills were usually rather prosperous men, and like most of the population at that time, the majority were farmers.

To operate the mill, the miller places the grain to be ground in the funnel-like hopper above his pair of millstones, after first taking out his toll. Then he opens the sluice gate that lets water into his water wheel. As the weight of falling water turns the water wheel, large gears turning smaller gears make the shaft turn faster, much as the large gear on the pedals of a bicycle will turn the smaller gear on the wheel more rapidly. This power is transmitted to a vertical spindle, upon which rests a large, flat disc of stone, often weighing a ton or more. This stone spins just above, but not quite touching, an identical stone set stationary in the floor of the mill. Both stones have a pattern of grooves cut into their faces. As one stone turns above the other, their grooves cross much like scissor blades. Grain falling through the hole, or "eye", in the runner stone is cut apart as it passes between the two stones. The miller can adjust the distance between the stones to regulate how finely the grain is ground. The milled grains moves around the cover that is over the stones, until it falls through a hole into the meal chest. From there it can be scooped up into a sack to be taken home for baking. See design plans.

Carding Mill

Before wool can be spun into yarn for knitting or weaving into cloth, it first must be brushed, or carded. This tedious task was successfully mechanized in the second half of the 18th century by several British inventors, principally Richard Arkwright and James Hargreaves. By the late 1780s carding machines began to be built in the United States, carding as much wool in minutes as a hand-carder could do in as many hours. By 1811 the federal government estimated that on average every town had at least one carding mill where farm families could bring their wool and pay to have it carded. This made the domestic production of cloth much easier by removing this time-consuming step. As textile factories multiplied in the 19th century, however, people stopped making their own cloth at home, and custom carding mills declined. Today, of course, there are no longer thousands of neighborhood carding mills in America catering to people who make their own cloth at home by hand. The same technology, however, is still used in modern cotton and woolen factories.

Since 1773, carding machines have had the same basic design as they do today. They consist of a series of round brushes that align wool fibers as the wool passes from one end of the machine to the other. Each cylinder is covered with bent iron wires, which grab wool in one direction and release it in another.

Clean but tangled wool is fed into the machine from a conveyor belt, called a feed apron. Two small cylinders--called licker-ins—transfer the wool from the apron to the tumbler, which deposits it on the large main cylinder. This cylinder carries the wool through the machine. Along the way, it is removed by workers. Strippers then take it from the workers and deposit it back on the main cylinder. Near the end of the machine, a fancy with long bristles fluffs the wool up on the main cylinder so that a doffer can remove it. The wool is rolled up into rolls or slivers for spinning as it passes between a fluted cylinder and a concave shell. See design plans.

See also

The Power of Water

Types of Wheels