164 HISTORY OF 



covered by Archimedes, to whom mankind have 

 been indebted for many useful discoveries. Hiero, 

 king of Sicily, having sent a certain quantity of 

 gold to be made into a crown, the workman, it 

 seems, kept a part for his own use, and supplied 

 the deficiency with a baser metal. His fraud was 

 suspected by the king, but could not be detect- 

 ed, till, applying to Archimedes, he weighed the 

 crown in water, and by this method informed 

 the king of the quantity of gold which was taken 

 away. 



It has been said, that all fluids endeavour to pre- 

 serve their level ; and likewise, that a body press- 

 ing on the surface, tended to destroy that level. 

 From hence it will easily be inferred, that the 

 deeper any body sinks, the greater will be the 

 resistance of the depressed fluid beneath. It will 

 be asked, therefore, as the resistance increases in 

 proportion as the body descends, how comes the 

 body, after it is got a certain way, to sink at all ? 

 The answer is obvious : From the fluid above 

 pressing it down with almost as great a force as 

 the fluid beneath presses it up. Take away, by 

 any art, the pressure of the fluid from above, and 

 let only the resistance of the fluid from below be 

 suffered to act, and after the body is gone down 

 very deep, the resistance will be insuperable. 

 To give an instance : a small hole opens in the 

 bottom of a ship at sea, forty feet, we will sup- 

 pose, below the surface of the water ; through 

 this the water bursts up with great violence ; I 

 attempt to stop it with my hand, but it pushes 

 the hand violently away. Here the hand is, in 



