CENTRIFUGAL FORCE. 



501 



The string represents the force of attraction, which binds all 

 our planets to the sun, and their satellites to the planets, while 

 the force that is employed in swinging the ball represents the 

 mysterious power that issues from the sun, and gives motion to 

 the planets. The metaphor is a very homely one, but it is 

 nevertheless correct. 



In the accompanying illustration are several examples of 

 Centrifugal Force as found both in Nature and Art. On the 

 left hand we have diagrams of some of the heavenly bodies, 

 showing the revolution of their offspring, so to call them, while 



CENTRIFUGAL FORCE OF HEAVENLY BODIES. 



CENTRIFUGAL FORCE OF "GOVERNORS OF ENGINE. 

 SLING. AMENTUM AND MOP. 



on the right are seen examples of Centrifugal Force as applied 

 to human use. For convenience' sake, the illustrations have 

 been separated into two portions. 



In the first of these illustrations we have the " Governor " 

 of the steam-engine, that wonderfully ingenious and simple 

 piece of mechanism which controls the force of the steam, and, 

 without the superintendence of man, acts almost as a living 

 being might. 



It is composed of two heavy metal balls, hinged, as shown in 

 the illustration, to a movable collar which slides up and down 

 the central rod. When, the engine is at work the Governor 

 revolves, and the harder it works, the more rapid is the revolu- 

 tion. Consequently, as it revolves, the balls diverge and draw 

 the sliding collar up the rod. 



Here lies the whole beauty of the invention. The sliding 



