48 CANDLES TOO TALL. 



dimensions that is, in what the mathematicians call a do 

 plicate, or double ratio. 



ENLARGEMENT AS THE SQUARES OF THE DISTAKOE8. 



Thus, in the engraving, if the distance from S to M is 

 twice as great as from S to m, M will be doubled in two 

 dimensions, and will, consequently, be four times as great 

 as m. 



John was much interested in the experiment which he 

 had made, and still more in the general statement of the 

 law which it illustrated. It is, indeed, very useful to know 

 this law, as our action in certain cases will be much influ- 

 enced by it. And few persons, unless they have had in- 

 struction on the subject, are aware of it. It is true that 

 every body knows that the nearer we are to the light the 

 better we can see; but it is not every body that knows 

 how much better that is, every one is not aware that by 

 diminishing the distance one half between the light and 

 his book, he makes the brightness of it upon the page four 

 times as great as it was before. 



A gentleman who had occasion to travel much in country 

 places where he often found it difficult to obtain a good light 

 for certain work of writing which he had to do, had a flat 



