ELECTRICITY. 3 



Q. Why is there a DARK RIM round this 

 focus? 



A. Because the rays of light, which 

 should have fallen there, are bent into the 

 focus, and the space around, (being 

 deprived of these rays) is accordingly 

 darkened. 



Q. Are ALL the rays bent into one point ? 



A. No, not quite all: and, therefore, 

 the rim round the focus is only slightly 

 shadowed. 



CHAPTER II. 



Q. What is the second chief source of heat ? 



A. ELECTRICITY. 



Q. What is LIGHTNING ? 



A. Lightning is only an Electric 

 Spark y taken from the clouds. 



Q. What causes the discharge of an electric 

 cloud ? 



A. When a cloud, overcharged with 

 electric fluid, approaches another which 

 is under-charged, the fluid rushes from 

 the former into the latter, till both have 

 the same quantity. 



B2 



