36 ON IMPROVING NATURAL KNOWLEDGE i 



infinitely remote, and that the end is as im- 

 measurably distant. 



But it is not alone those who pursue astronomy 

 who ask for bread and receive ideas. What more 

 harmless than the attempt to lift and distribute 

 water by pumping it ; what more absolutely and 

 \ grossly utilitarian ? Yet out of pumps grew the 

 discussions about Nature's abhorrence of a vacuum ; 

 and then it was discovered that Nature does not 

 abhor a vacuum, but that air has weight ; and 

 that notion paved the way for the doctrine that 

 all matter has weight, and that the force 

 which produces weight is co-extensive with the 

 universe, in short, to the theory of universal 

 gravitation and endless force. While learning 

 how to handle gases led to the discovery of 

 oxygen, and to modern chemistry, and to the 

 notion of the indestructibility of matter. 



Again, what simpler, or more absolutely prac- 

 tical, than the attempt to keep the axle of a 

 wheel from heating when the wheel turns round 

 very fast ? How useful for carters and gig 

 drivers to know something about this; ami how 

 good were it, if any ingenious person would find 

 out the cause of such phenomena, and thence 

 educe a general remedy for them. Such an 

 ingenious person was Count Rumford ; and he 

 ^ und his successors have landed us in the theory of 

 the persistence, or indestructibility, of force. Ami 

 in the infinitely minute, as in the infinitely great, 



