Understanding Maryland Records
Water mills provided power from colonial times until the early 20th century, replacing the grinding of grain by hand, Native American style, using an ox, horse, or mule to turn a grinding wheel. As early technology advanced, mills were used for a wide variety of purposes, and the 1850 industrial census, as well as the many deeds and advertisements concerning mills, used terms that may require clarification:
Grist mill - Mill which ground corn into meal.
Flour mill - Mill which ground wheat, rye, or buckwheat into flour. Flour mills developed later than grist mills because flour was more expensive than meal and corn was easier to grow and harvest than other grains.
Merchant mill - A miller purchased grain from farmers, ground it, and then sold the meal or flour, rather than grinding grain in return for a percentage of meal or flour.
Offal - Sometime spelled "awful," it was a byproduct of the milling, consisting of screening, bran and shorts of wheat, which was used for feed.
Overshot mill wheel - This referred to a mill dam and mill race. The water was directed to the top of the overshot wheel and because the paddles of the overshot wheel were formed into buckets, when the water struck the upper blades, it turned the wheel not only by the force of the water but also by the force of gravity as the water in the buckets fell.
Bone mill - Ground bones into bone meal which was used as fertilizer.
Plaster mill - Plaster or plaister was a term used in the 1800's to denote land plaster which was finely ground gypsum applied as a fertilizer and soil stimulant for crops. Locally produced, it was used until the advent of the railroad made it less expensive to import guano.
Clover mill - It separated the seed needed for planting from the clover itself. Rather than being trod by horses or flailed by hand, which created obnoxious dust, harvested clover was brought to the mill. The millstone rasped the clover seed, vibrating screens took out straw, and fanning machines blew away chaff.
Manufactory - Cotton, woolen, and paper manufactories were simply mills which used water power to produce these items. Early woolen mills were usually called fulling mills. The sumac manufactory listed in the Montgomery County 1850 industrial census used a horse and three mules to turn 150 tons of sumac into 130 tons of sumac sauce. One meaning of sumac is the leaves, peduncles, and young branches of sumac. This would have a high content of tannic acid, and apparently was ground into a sauce by the horse and mules, and the sauce sold for use in tanning and dyeing.