60 APPLIED SCIENCE 



from the center of gravity is, as we have noted, called 

 centrifugal force. This force is overcome by the cohesive 

 force of the material that composes the fly-wheel, or the 

 adhesive material that holds the particles of the grindstone 

 together. This cohesive or resisting force is called centripetal 

 force and is directed toward the center. 



The principle of centrifugal force is utilized to great ad- 

 vantage in the construction of hydroextractors, i.e., machines 



designed to throw 

 off the water con- 

 tained in dyed or 

 scoured fabrics, in 

 sugar in a liquid 

 state, and in bolts 

 and nuts or other 

 small metal parts. 

 All centrifugal ma- 

 chines operate on 

 essentially the same 

 principle. Figures 

 37 and 38 show a 

 machine designed 

 to extract the liquid 

 from solid or semi- 

 solid matter by cen- 

 trifugal force; this 



FIG. 37. Centrifugal Machine. Showing has- type of machine is 

 ket about to be lowered into casing. 



known as a chip 



wringer. Figure 37 shows the basket about to be lowered 

 into its casing; the machine is then ready for use. Figure 

 38 shows the machine open with the basket inverted, the 

 material having been dumped out. 



