No.l. 



No. 3. 



W" '• ' '• L- 



4r^^ ■ * "i DECLINATION 



^w.^- /J Lines of equal disCurbance from cheNormall 

 V) ' // --dp,note Chat tlieneedleis drawn to WesCwardJ 



i) / \ Eascwardi 



U ^ \ der\ote5 that there is no disC/urbance | 



+185 



HORIZONTAL FORCE. 



Lines of equal disCurbance from theNormal. 

 denote increased valuea of the 



horizontal force. 

 denote decrease in the values of 



the horizontal force. 

 denotes that there is no distuihemce 



No. 2. 



Lines of equal disturbance from, tbifi Nonral 

 -denote that tk North seeking end cf 



the needle is drawn domwdrds. 

 denote Chat the North seeking end. cf 



the needle is repelled upafards. 

 maj±ed denote no disturbance. 



Scale of Nautical Miles. 

 Chart of Magnetic Disturl>uiices. 



