Whirling Tables and Accessories
     The Whirling Table Apparatus has a history dating back at least to 1713. It is shown in A Course of Mechanical, Optical, Hydrostatical and Pneumatical Experiments, To be perform'd by Francis Hauksbee; and the Explanitory Lectures read by William Whiston, published in London that year. 

   In the experiment at the right, a body G in a tilted glass tube has the necessary centripetal force supplied by a string passing down the center of the whirling table with a weight suspended from it.

   This rotator, in use in lecture demonstrations at Kenyon College, is by James W. Queen of Philadelphia, and is listed, fully equipped at $40.00 in the 1888 catalogue. The catalogue copy shows the Figure of the Earth apparatus.
   In this whirling table attachment, a large and a small ball are connected by a tube sliding on a smooth rod. If the center of mass is coincident with the whirling axis, the balls have no radial motion. But, if the center of mass is moved to the side by sliding the unit in either direction, centripetal force will cause the unit to slide to one end when the system is whirled about a vertical axis. This apparatus is at Colby College.
   This whirling table attachment, in the collection of St. Marys College in Notre Dame, Indiana, shows the action of bodies of various densities in a rotating frame of reference. The glass tubes are filled part way with water; on one side is a small amount of mercury, and on the other side is a cork. When the system is spun about its axis of symmetry, the more dense object flies outward: on one side the mercury rises through the water and goes to the upper end of the tube, and on the other side the water is on top and the cork is on the bottom.
   This is the only piece of apparatus I have seen thus far by Millington of Philadelphia. It is in the collection of Colby College in Waterville, Maine, and is used to study centripetal force. Cords connect the two sliding masses with the platform in the middle, on which weights may be placed. These weights supply the centripetal force needed to maintain the weights spinning at a constant radius.

   This is the same experiment shown on the whirling table from Hauksbee and Whiston at the top of the page.

   Troughton and Simms of London made this double whirling table, with each side equipped with apparatus similar to the picture above to study centripetal forces. This apparatus was made after 1832, when Troughton became Troughton and Simms, and was donated by the University of Alabama to the Smithsonian Institution. This is a Smithsonian photograph. 
 
The device below is at Case Western Reserve University in Cleveland, Ohio. The centripetal force to keep the sphere at a constant radius is supplied by a calibrated spring in the interior of the long, hollow tube on the left.    








   These two centripital force devices are in the collection of Case Western Reserve University in Cleveland, Ohio.
They are placed in a rotator and spun. The necessary centripetal force to keep the horizontally-sliding masses in place is

supplied by the large brass weight, which is free to slide up and down and is attached to the rotating masses by strings. The upper device is by Gaertner of Chicago, while the lower one is unmarked.


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