GEOMETRICAL PROPERTIES OF THE LINES OF 

 FORCE PROCEEDING FROM 

 (a) A SYSTEM CONSISTING OF AN ELECTRI- 

 FIED PLANE AND AN ELECTRIFIED 

 LINE PARALLEL TO THE PLANE. 

 (6) A SYSTEM CONSISTING OF AN ELECTRI- 

 FIED PLANE AND AN ELECTRIFIED 

 POINT.* 



Wm. H. Roever. 



(a) The curve representing a line of force proceeding from 

 a system consisting of an electrified plane and an electrified 

 line parallel to the plane, is the locus of the intersection of 

 two straight lines having inotions in a plane which is perpen- 

 dicular to the electrified line ; one line having a 7notion of 

 uniform isolation about the electrified line as an axis, and the 

 other a motion of uniform translation perpendicular to itself 

 and parallel to the electrified plane. 



The force at a distauce r from an electrified straight line 



whose charge is X per unit length is / = —;-. The flow of force 



2\ 

 from a unit length of line is — ^ X 27rr = 47rX. Hence the 



flow of force from a unit length of line between two planes 

 which ii! 

 other is 



Ar=47rX 



27r 



which intersect in the line and make an angle w with each 



N= 47rX -- = 2\co. 



The force at a finite distance from an infinite electrified plane 

 whose charge is a per unit area is i^= 27r(T. Hence the flow 



* Read before The Academy of Science of St. Louis, December 7, 1896. 



(273) 



