The Caiise of Life and Motion 29 



towards a magnet, and therefore, any suscep- 

 tible body with indifferent or weak polarity 

 would be impelled to it. 



The slight extra force which causes the mag- 

 netic needle to lie with its axis in a plane, or 

 nearly so, with the earth's axis, is probably 

 caused by two sets of forces, one from a 

 northerly and the other from a southerly direc- 

 tion, and crossing each other at unequal angles 

 on true meridian lines. There is nothing pecu- 

 liar about these forces except their somewhat 

 greater energy. Therefore, the energy about a 

 magnet is not materially changed by any special 

 position it may have, although it may retain its 

 molecular condition, best with its axis coincid- 

 ing with that of the magnetic needle. In a 

 number of instances, pieces of magnetic ore have 

 been found, with several diverse poles in a single 

 piece. 



Since the magnet derives its apparent power 

 from certain impeded vibrations which pierce it 

 in all directions, and since the power is principal- 

 ly superficial, it would seem that a magnet which 

 should have the greatest surface with the least 

 transverse sectional area, would be the most pow- 

 erful, all other things being equal; therefore, a 

 magnet with a star shaped section, would prob- 

 ably be more efficient than the ordinary kind. 



If a piece of steel should displace more total 



^r W " ~ * J^ ^V-.. 



(UNIVERSITY^ 



