II. 



CURIOSITIES OF STEAM AND VAPORISATION, 

 i. Strong Vessel burst by heating Water in it. 



OUR last experiment was the bursting of a 

 strong vessel by cooling water inside it till 

 freezing took place. The paradox here is 

 that the opposite condition, the heating of the 

 water, will produce the same effect. 



The fact is only too familiar, as illustrated 

 by the bursting of steam boilers, but it may be 

 illustrated in a more convenient way than 

 that we need not imitate the ingenuity of 

 Charles Lamb's Chinaman, Ho-ti, who invented 

 the art of burning down a cottage to procure 

 roast pig. Further, it is desirable to consider 

 by what agency, in detail, an opposite cause 

 can produce a similar effect. 



First, then, for the experiment. If it be 

 desired to show in the laboratory the bursting 

 power of heated water, it will, of course, be 

 necessary to take care that the burst can do 

 no harm. For this purpose it will be best to 

 have one part of the vessel made much weaker 

 than the rest in order that it may certainly be 

 the part to burst, and may be directed so that 

 the explosion can hurt no one. For this pur- 

 pose the strong iron cylinder closed by a thin 



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