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A New Form of Rotator. 



a half inches square by about three feet in length. This 

 bar carries the driving-wheel and pulley by which the 

 motion is obtained. The steel shaft of the pulley passes 

 through the bar and is furnished with a screw at each 

 end. By this means articles may be firmly attached 

 to a vertical axis projecting either upward or downward 

 as may be most desirable. A hook accompanies the 

 lower end of the shaft from which bodies may be freely 

 suspended. The bar carrying the driving wheel and pul- 

 ley, being hinged upon the table, is held firmly in place 

 by a catch. By sliding this catch, the bar turns upon 

 its hinges, carrying the wheel and pulley with it, and 

 thus throws the shaft into a horizontal position, instantly 

 adapting it to receive attachments for optical disks, Geisler 

 tubes or other pieces which must rotate in a vertical plane. 



It does not seem that this rotator needs to be essentially 

 more costly than the old style of whirling table ; that it 

 has capacity to receive attachments for all varieties of ro- 

 tary motion in illustrating the different departments of 

 physics would seem to make it more desirable than any 

 hitherto devised. 



