14 ELEMENTS OF ELECTRICAL ENGINEERING. 



Fig. 6 shows the lines of force encircling a straight electric wire. 

 The black circle at the center of the figure is a section of the wire 

 and the wire is perpendicular to the plane of the figure. 



Fig. 6. 



10. The composite magnetic field produced when a straight elec- 

 tric wire is stretched across a magnetic field, which, but for the 



Fig. 7. 



presence of the electric wire, would be a uniform field. The mag- 

 netic field between the flat-ended magnet poles, Fig. 5, is nearly 



