LESSORS IN ELECTRICITY. 



PICK 39. 



the leaves immediately diverge, by the 

 electricity driven from your left hand to 

 the electroscope. 



Here the nail may be electrified either 

 by connecting it with the prime conduct- 

 or oft he machine, or by rubbing it with 

 an excited glass rod. Indeed, I should 

 prefer your resorting to the simplest and 

 cheapest means in making these experi- 

 ments. 



21. Franklin's Cascade Battery. 



As a thoughtful and reflective boy or 

 girl you cannot, I think, help wondering 

 at the power which your thorough mas- 

 tery of the principles of induction gives 

 you over these wonderful and complica- 

 ted phenomena. By those principles the 

 various facts of our science are bound to- 

 gether into an organic whole. But we 

 have not yet exhausted the f ruitf ulness of 

 this principle. 



Consider the following problem. 

 Usually we allow the electricity of the 

 outer coating to escape to the earth. 

 Suppose we try to utilize it. Place, then, 

 your jar, A B, fig. 40, upon vulcanized 

 india-rubber, and connect by a wire B c 

 its outer coating with the knob or inner 

 coating of a second jar c D. "What will 

 occur when the first jar is charged ? 

 Why, the second one will be charged also 



by the electricity which has escaped from 

 the outer coating of the first. And sup- 

 pose you connect the outer coating of 

 the second insulated jar with the inner 



