Coil Top Shakers

The term coil top does not refer to the shaker directly but to the unique top that it possesses. As the trade ad tells us, the shaker was patented on July 26, 1881. These pieces are hard to find in my opinion and especially in colored glass! The bottom of these shakers is embossed with the Eagle Manufacturing Co. and the patient date. The patient date of this particular shaker says July 26th 1888. I'm not sure of this discrepancy, but the positioning of the date letters and numbers suggests that they were adjustable within the mold.
As you can see, the top is like a spring. In the center of the spring lid protruding down inside the shaker in a corkscrew shape is an agitator to break up the salt. I would suspect, by pushing down on the lid, the agitator would move up and down thus breaking up the clumped salt. When the shaker is used, the salt would pass through the opening between the coiled spring.