One of tours we did was at the Mission San Jose. It is one of the missions built along the San Antonio River. See here for more info: http://www.nps.gov/saan/historyculture/sanjosehistory1.htm
It was originally built in the early 1700s - about 300 years ago. It was destroyed in war and what was left fell into disrepair. The WPA rebuilt the mission in the 1930s.
The mission wasn't just the church - it was the community. The Indians lived in what were essentially apartments built into the protective walls. The Indians were originally hunters and gatherers, but the Fransiscans (monks) taught the Indians how to farm. They built miles of irrigation ditches (called acequias) to bring water from the San Antonio River to their farms.
But these irrigation ditches were used for something else as well. When the WPA was rebuilding the Mission San Jose, they uncovered brick-lined pits and channels. What they had found was the foundation of a grist-mill for grinding wheat! They then rebuilt the grist-mill and it works today!
This is the exterior of the mill - water wheel below, mill above.
It was so interesting to see how a grist-mill worked - no electricity, no engines, no machines. It doesn't get much more "green" than how it was done in the 1700s.
The water wheel at work.
The water from the irrigation ditches flows into a channel and then into a 9' deep pit. This pit creates water pressure. A gate is opened and the water flows down and into the water wheel. (Yes, that is a horizontal water wheel!). This turns the wheel which turns the shaft that is attached to the mill above.
The mill wasn't very big - I was expecting something much larger. The handle on the far left side is essentially the "on-off switch." This lever opens and closes the gate that allows the water flow to operate the water wheel. The funnel on top of the mill holds the whole wheat kernels. The round disc you see is a granite millstone. Two stones are stacked on top of each other, with space between them. The bottom stone is stationary and the top stone is turned by the shaft from the water wheel. Wheat falls through the hole in the funnel to the hole in the millstone. The wheat is then ground between the two stones.
A millstone (not from this grist-mill)
For more info on millstones - check out this site: http://www.angelfire.com/journal/millrestoration/millstones.html
As the top stone turns, the wheat is ground into a fine flour. The texture of the flour can be changed by altering the space between the two stones.
The flour is then pushed to the outside and down into a waiting bucket.
Wheat being milled into flour.
After explaining how the mill worked, the park ranger passed around a bowl of the flour for us to touch. An older man, obviously from the city, commented "Can you eat this?" My Love, with the bowl in his hand, took a pinch of the flour and put it in his mouth. "Yep!" he said. The man then said "I would be afraid it would have glass or something in it." (There was no glass anywhere...)
It has become more and more obvious that most people don't understand where their food comes from. Yes, we saw that wheat actually being ground - but since it wasn't white, bleached, enriched, and in a paper bag on the grocery shelf, it must not be flour!
It's amazing how far removed we are from the source of our food. As each generation depends more and more on others to produce the food they eat, that knowledge gets lost. It is my job, and the job of every other farmer and rancher out there, to educate the nation about what we do and how we do it.