282 SCIENCE OF COMMON THINGS. 



Places dangerous in a thunder storm. How a tree influences lightning. 



Not less than two hundred and fifty thousand miles 

 per second. 



1836 Why does lightning sometimes kill men and leasts f 



Because, when the electric current passes through a 

 man or beast, it produces so violent an action upon the 

 nervous system, that it destroys life. 



1337* When is a person struck dead by lightning 1 



Only when his body forms a part of the lightning's 

 path j that is, when the electric fluid (in its way to the 

 earth) actually passes through his body. 



1838 Wliat places are most dangerous during a thunder storm f 



It is very dangerous to be near a tree or lofty building. 



1839 Why is it dangerous to be near a tree or lofty building during a 

 thunder storm f 



Because a tall, pointed object (like a tree or spire) 

 will frequently discharge a lightning cloud ; and if any 

 one were standing near, the lightning might diverge 

 from the tree and pass through the fluids of the human 

 body. 



1S4O How can a tree or spire discharge a lightning cloud f 



A lightning cloud, floating over a plain, may be too 

 far off to be discharged by it ; but as a tree or spire 

 would shorten this distance, it might no longer be too 

 far off to be discharged. 



For example : If a lightning-cloud were seven hundred yards above the 

 , earth, it might be too far off to be discharged ; but a tree or spire fifty 

 yards high would make the cloud only six hundred and fifty yards off a 

 conductor ; in consequence of which the cloud might be instantly dis- 

 charged. 



1841 What parts of a dwelling are most dangerous during a thunder- 

 storm f 



The fireplace (especially if the fire be lighted). It is 

 also imprudent to sit close by the walls. 



1843 Why is it dangerous to sit before afire during a thunder storm f 



Because the heated air and soot are conductors of 

 lightning, especially when connected with such excel- 

 lent conductors as the stove, grate, or fire-irons. 



1843 Why is it dangerous to lean against a wall during a thunder 

 storm f 



