Model: 117 Balance Pump
This type of pump was an early form, operated by a man swaying from right to left over the center of the bridge. Slaves and criminals were commonly used and so worked out their sentences in labor. The two plungers represent valve pumps.
[Virginia Downward & William M. Clark, 1930]

[Editor’s Note: This is an ancient form of pump. Clark copied this model from Figure 465 of Henry T. Brown's 1868 catalog of mechanical movements. The device represents a double slider-crank mechanism. FCM]

Francis Moon 2005-00-00

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