Mill Pond I
Do you know that Boston had a power plant back in the 1700's? It didn't
burn any fuel, and It didn't generate electricity. Instead, their "power plant"
harnessed the tides and used water wheels to turn a giant grist mill stone.
These stones ground corn so the settlers could make bread. Recently,
construction of the Big Dig unearthed one of the original mill stones.
Ever seen how water rushes under bridges near the shore when the
tides are changing? The settlers created this situation by building a
Mill Dam to enclose a pond which was now open to the ocean on only
one side, through a narrow canal. When the tide rose, water rushed into
fill the pond, and would drive the water wheel. When the tide went out
the water would rush the other way, driving the wheel the other way.