CHAPTER I 

 A DEFINITION OF SCIENCE 



" Knowledge comes, but wisdom lingers." 



Tennyson. 



THE word " Science" has in recent years 

 received a more precise and restricted mean- 

 ing than that attached to it in former times. 

 Derivatively of course it simply means know- 

 ledge; and in the time of Johnson it was 

 associated with any species of knowledge. 



I have used it in this book in its more 

 modern application, and I mean by it those 

 branches of knowledge only which are associ- 

 ated with the law of numbers, of dimension, 

 of motion and of time which is its measure- 

 ment, with trigonometry, conic sections, the 

 differential calculus and all the higher mathe- 

 matics ; with all the discovered laws of Nature 

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