Salt of the Hayward Shoreline
Solar evaporation of salt is most favorable where the climate is mild; little rainfall and constant wind are ideal using this method of producing salt. The wind coming into the San Francisco Bay Area made a wind-powered pump a highly logical method to extract salt from ocean water. In the 1870’s, Andrew August Oliver designed and built the Archimedes screw pump to transfer brine from one evaporation pond to another. The concept behind this screw pump comes from the Greek mathematician Archimedes (287-212 B.C.E.). Original pumps used in Egypt, Rome, and Japan were manually turned by hand and the windmill technology was added in Holland during the 17th century.
The Archimedes screw pump itself is a continuous spiral enclosed in a shaft that raises water upward when rotated. With Oliver’s design and a 25 mph wind, the pump can raise 1,500 to 2,000 gallons of water per minute. Oliver’s pumps were the longest surviving wind powered pumps to be used and were only replaced by electric pumps in the early 20th century.
In 1984 the American Society of Mechanical Engineers designated the Archimedes Wind-powered Screw Pump to be a regional historic mechanical engineering landmark. One can see the reproduction of these screw pumps today (though they are quite tattered and beaten by the elements) at the Hayward Regional Shoreline near the Hayward side of the San Mateo Bridge.