TERRESTRIAL MAGNETISM, ETC. 267 



C.B., R.N., and Lieutenant (now Captain) Creak, 

 R.N., from the results of observation in all parts of 

 the world, collected, analyzed, and exhibited, in 

 fully detailed charts for the epoch of 1840 45, by- 

 Sir Edward Sabine, R.A., K.C.B., in the Trans- 

 actions of the Royal Society. 



The annexed diagrams (Fig. 36) of the northern 

 and southern hemispheres are drawn according to in- 

 formation taken from these charts. They exhibit, 

 on a plan first proposed by the French navigator 

 Duperrey, and largely used by Faraday in his 

 drawings of lines ot magnetic force, the lines of 

 direction of the mariner's compass in different parts 

 of the world, referred to above. 



A traveller starting from any point of the earth's 

 surface and travelling always along the line shown 

 by the compass needle, and in the direction of the 

 north point of the compass card, would be led to a 

 certain point in the Island of Boothia, in about 

 1 00 of west longitude, and 70 of north latitude. 

 This point is the earth's north magnetic pole. Or, 

 if he travels along the same line but in the contrary 

 direction, that is to say in the direction of the south 



