no 



ADVANCED ELECTRICITY AND MAGNETISM. 



is here said concerning the given transverse slice of the ship is 

 true of every transverse slice, and therefore the field at C due 



-fr O c - 



stern 



Fig. 74. 



to the transverse magnetization of the entire ship when its bow 

 points east or west (magnetic) is towards the south, and con- 

 sequently the compass is not deflected. 



68. Peculiarities of quadrantal error. From Figs. 73 and 74 

 it is evident that the temporary magnetism of the ship weakens 

 the field at the compass (T opposite to H' in direction, so that 

 the resultant of T and H f is less than H') when the ship heads 



bow 



d> 



* 



B-bar 



bow 



Fig. 75. 



Fig. 76. 



