250 SCIENCE AND METHOD. 



dren, who will be warned, before they are taught the 

 ordinary mechanics, that it has had its day, and that 

 at most it was only good for such an old fogey as 

 Laplace. Then they will never become familiar with 

 the ordinary mechanics. 



Is it good to warn them that it is only approximate? 

 Certainly, but not till later on ; when they are steeped 

 to the marrow in the old laws, when they have got 

 into the way of thinking in them, and are no longer 

 in danger of unlearning them, then they may safely 

 be shown their limitations. 



It is with the ordinary mechanics that they have to 

 live ; it is the only kind they will ever have to apply. 

 Whatever be the progress of motoring, our cars will 

 never attain the velocities at which its laws cease to 

 be true. The other is only a luxury, and we must not 

 think of luxury until there is no longer any risk of 

 its being detrimental to what is necessary. 



