CHAP, ii.] ELECTRICITY AND MAGNETISM. 



117 



in the south-east. We might similarly construct a 

 magnetic map, marking it with lines joining places 

 where the dip was equal ; such lines would be called 

 Isoclinic lines. In England they run across the map 

 from west-south-west to east-north-east. On the globe 



Fig, 67. 



the isogonic lines run for the most part from the north 

 magnetic pole to the south magnetic polar region, but, 

 owing to the irregularities of distribution of the earth's 

 magnetism, their forms are not simple. The isoclinic 

 lines of the globe run round the earth like the parallels 



