The centerpiece of Historic Mill Creek Discovery Park is the reconstructed, water-powered sawmill. Watching it saw boards is often a highlight of a visit to the park. As the saw and its frame move up and down more than 100 times a minute, one can feel and see the power contained in the small creek. The power comes not from the size of the creek but from the pressure of water held behind the dam. The water is directed from the mill pond, ten feet above the water wheel, through a wooden sluice which empties into a large wooden box called a crib. A gate at the bottom of the crib is opened by the mill operator, and the water that gushes out falls with great weight on the flutter wheel, turning it. The flutter wheel is about 4 feet long and has 10 fins projecting from its sides. At the end of the flutter wheel is a crank, which is attached to a long wooden pole called a “pitman arm,” because it does the same job that the “pit man” did when boards were sawn by hand. As the wheel and crank rotate the pitman arm moves up and down and, being connected to the bottom of the saw frame, moves the saw blade up and down.
The mill also moves the log into the saw blade. A ratchet system attached to the top of the frame pushes against a large “rag wheel,” slowly turning it and the “rag shaft” connected to it. Notches in the rag shaft push against large wooden teeth on the bottom of the carriage on which the log rests. Each up-and-down stroke of the saw blade moves the saw carriage and log into the blade one-third of an inch. The process sounds complicated, but when you watch it the process works smoothly (but noisily).
The mill contains a second wheel of a different design, called a “tub wheel.” It looks like a wagon wheel with slanted fins inside it so that a small quantity of water spins the wheel rapidly. By pulling a lever, the mill operator can engage the tub wheel to the rag wheel, putting the log carriage into reverse.
Although archaeologists never found the exact location of the sawmill at Mill Creek, they had a solid idea of what it looked like from a 1795 book by Oliver Evans, an inventive American millwright. The book, The Young Millwright and Miller’s Guide, had detailed drawings and descriptions of an 18th-century mill. Architects were also greatly aided in their reconstruction by what they learned from examining the piece of original saw blade found at the site and from boards and stubshots cut in the mill that had been found in the 1825 Mission House on Mackinac Island. Marks on the boards showed the rake, or angle, of the saw blade and the set of the teeth. They also showed that the log advanced into the saw blade at ½ inch per stroke.
When work began on the reconstruction, however, no one had built a water-powered sawmill for more than 100 years, and very few examples still existed. So, to be sure his plan would work, the designer built a scale model. The model, which worked perfectly, is now in the David A. Armour Visitor’s Center at Historic Mill Creek Discovery Park.