P L A 



For the telescopic appearance of the Planets see Telescope. 



PLANETS, disturbances occasioned by their mutual action upon each 

 other. -( Pla if fair. ) 



The orbit of every planet, by the action of the other planets, is chan- 

 ged in all its elements bat t\vo ; the mean motion, and the mean distance 

 from the sun. Thus in Mercury and Venus the line of the nodes, thy 

 20? 



