154> HISTORY OF 



and grown more bulky, by freezing, than the 

 water which remains unfroze. Mr Boyle, how- 

 ever, put the matter past a doubt, by a variety of 

 experiments. Having poured a proper quantity of 

 water into a strong earthen vessel, he exposed it, 

 uncovered, to the open air, in frosty nights ; and 

 observed, that continually the ice reached higher 

 than the water before it was frozen. He filled 

 also a tube with \vater, and stopped both ends 

 with wax : the water, when frozen, was found to 

 push out the stopples from both ends ; and a rod 

 of ice appeared at each end of the tube, which 

 showed how much it was swollen by the cold 

 within.* 



From hence, therefore, we may be very certain 

 of the cold's dilating of the water ; and experi- 

 ence also shows, that the force of this expansion 

 has been found as great as any which heat has 

 been found to produce. The touch-hole of a 

 strong gun-barrel being stopped, and a plug of 

 iron forcibly driven into the muzzle, after the 

 barrel had been filled with water, it was placed 

 in a mixture of ice and salt j the plug, though 

 soldered to the barrel, at first gave way, but 

 being fixed in more firmly, within a quarter of 

 an hour the gun-barrel burst with a loud noise, 

 and blew up the cover of the box wherein it lay. 

 Such is its force in an ordinary experiment. But 

 it has been known to burst cannons, filled with 

 water, and then left to freeze ; for the cold con- 

 gealing the water, and the ice swelling, it be- 



* Boyle, vol. i. p. 610. 



