PRESSURE AND RESISTANCE. 117 



water than is contained in an ordinary mill-pond. 

 It is true that if we were to try such an experiment 

 we should have some difficulty in finding a cylinder; 

 because it would give way, and give way with a 

 dreadful explosion, if it were not, at its very weak- 

 est point, more than able merely to balance the 

 weight of the vast fleet or the entire hill. With us 

 such vessels would be out of the question; but 

 still, as we have no occasion to lift large fleets or 

 entire hills, for we take hold of other natural 

 principles, and make the fleets sail, and dig through 

 the hills, or break them up piece and piece by 

 gunpowder, we can have cylinders for water- 

 presses as strong as we have any use for. But 

 nature is not limited in her instruments or opera- 

 tions as we are. We are spectators, and can only 

 imitate that which we have found out ; whereas 

 that which we call nature is the thing itself which 

 we observe, all substances and all their proper- 

 ties. Thus in the resistance of pressure, nature 

 can have her apparatus strong, up even to the 

 tearing asunder even the globe itself; and we 

 know not how many powers in addition to those 

 with which we are acquainted there may be linked 

 together to prevent that catastrophe ; but we do 

 know that if a carriage-wheel, made of the toughest 

 iron, were made to trundle round at any thing 

 nearly equal to the rate at which the earth 

 moves, it would not only be in a moment scat- 

 tered to atoms, but those atoms would speed away 

 on fire, burning and being burned with more in- 

 tensity than any furnace that we could kindle or 

 even imagine as being heated by all the art of the 

 founder, and spread conflagration far and wide. 

 Yet that motion of the earth bends not the slightest 



