CHAPTER XV. 



MAGNETISM, 



Explanation chapter. To show difference between Magnetism and Elec- 

 tricity. Prof. Grove and Faraday. Electricity not a force at all. 

 Arrangement of a galvanic battery, How telegraphing is accom- 

 plished. Telegraph worked by grass. A few facts about magnetism. 

 Well known and not generally known. Faraday's misfortune. 

 Born too soon. The " Magnetic curves " explained. Tyndall 

 astray again. Polarity of iron railings. How the polarity of mag- 

 f netism changes with position. Sir Isaac Newton's apple. The 

 Law of gravitation upset. How magnetism is a weight, and how 

 it affects weight. What Newton wished to discover. The cause 

 of deviation of compasses in iron ships. 



This chapter is introduced more by way of explanation than 

 anything else, in order to distinguish Magnetism from electri- 

 city. We described in our second chapter on matter and its 

 force, the leading characteristics of magnetism, and every chap- 

 ter since, has had more or less reference to it. 



Being the universal force in nature, we could not explain the 

 cause of any phenomena without mentioning it; and the conse 

 quence is, that nearly every sitcceeding chapter will also contain 

 something new regarding it, according as the subject matter 

 appears in different positions and conditions. 



Prof. Grove in his " Correlation of Physical Forces," says : 

 44 Magnetism, as was proved by the important discovery of 



