Physical description
Letter dated November 12, 1937 to Paul A. Douden & Co. from W. W. Eden, Mgr. F. W. Woolworth Co. W. W. Eden mentions that since installing Scale Buoys over two years age we have had no trouble from scale or lime deposits at all in our system, except for the water used for cooling the natural gas engines. This water didn't come in contact with the Scale Buoys and they contemplated additional units to treat it. They also had no scale in the coffee makers and dish washers.