178 POWER OF LATERAL COMPRESSION. 



sive force was exerted on the opposite sides of the seg- 

 ments of our cradle clock, which, as it formed under the 

 counter, presented a nearer approach to the wedge in- 

 fluence, and thus imperceptibly tended to lift the vessel. 

 If the fluid water would effect this, surely it will not be 

 contended that solid ice could not. 



This wedge power, having no yielding surfaces late- 

 rally, I assume to be one, if not the grand, cause of the 

 heavy cracks, or reports, before alluded to, and termed 

 " cracking of bolts," and which ceased entirely about 

 January, as before stated. 



Now, reverting to the action of freezing on different 

 fluids in slight glass cylindrical jars, they would, if con- 

 fined at the orifice, under common reasoning, be broken 

 at the moment of complete congelation, by the sudden 

 expansion. But my experience teaches me that this is 

 not a law, and that under the course of freezing, we have 

 first, the coating of fine crystals on the outer exposed sur- 

 faces ; next, the accumulation of the floating separate 

 crystals into a sludgy, creamy snow or ice ; and finally, 

 consolidation and expansion. This latter is an enormous 

 power ; but its action, I find, depends very much on the 

 vessel in which it is contained. I never, freezing at tem- 

 peratures at 51, found it break or crack any glass 

 vessel ; but I noticed that where it froze in the long 

 tube (nine inches by five-eighths bore), it elongated the 

 ice, and forced it vertically out of the tube to the extent 

 required by Nature. In bottled fluids, which being 

 corked offered resistance, I found they were burst at the 

 shoulder near the neck when of the wine-bottle form ; 

 but where beer or ale was exposed in champagne- 



