A look at the millstones, ready to grind grain, in Peirce Mill, Rock Creek Park, Washington DC. Note the long beam at the top connected to the vertical wooden "beam" used to open the sluice outside, and also on the left, the wooden "pedestals" with cranks, to adjust the height of the millstones. The Peirce Barn is just visible outside through the window. Note also the large electrical box in the background. An electric motor pumps the water to run the water wheel. Originally (of course) Peirce Mill ran off of water impounded from a dam across Rock Creek, but does not now.
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<span class="int-own-work" lang="en">Own work</span>