52 CANDLES TOO TALL. 



the covering, but that makes no difference. The areas of 

 surfaces are as the squares of any corresponding lines 

 that is, any lines bearing the same relation to the two sur- 

 faces compared. 



Lawrence explained these things to John, who listened 

 with close attention, and asked many questions, and at 

 length said, 



" Now take your pencil and write what I shall dictate to 

 you, to be copied into your book of notes." 



So John took his pencil, and Lawrence dictated as fol- 

 lows : 



" FUNDAMENTAL PRINCIPLE. 



" In all cases of force or influence of any kind radiating 

 from a centre, and not intercepted on its way, the intensity 

 'at any point is inversely as the square of the distance from 

 the centre." 



" And now," said John, after he had written this, " it is 

 high time for me to begin my half hour's study." 



" But your half hour's study is over," said Lawrence. 



"Over?" said John, surprised. 



" I think so," said Lawrence. " Let me see." 



So saying, he took out his watch and said, "Yes, and ten 

 minutes more. Listening to instructive explanations from 

 me, you know, is to be counted for study, if you listen at- 

 tentively and try to understand them." 



" Good !" said John, in a tone expressive of great exulta- 

 tion ; " I thought I should have half an hour more of arith- 

 metic before I could go to bed ; but now I can go to bed 

 at once, for I am tired and sleepy." 



So saying, he put away his books and papers, and pre- 

 pared to go to his room. 



" But, Lawrence," said he, " what was the particular 



