CHAPTER V. 



THE ACTION OF FROST IN WATER-PIPES AND ON BUILDING 

 MATERIALS. 



POPULAR science has penetrated too deeply now to render 

 necessary any refutation of the old popular fallacy which at- 

 tributed the bursting of water-pipes to the thaw following a 

 frost ; everybody now understands that the thaw merely 

 renders the work of the previous freezing so disastrously evi- 

 dent. Nevertheless, the general subject of the action of freez- 

 ing water upon our dwellings is not so fully understood by all 

 concerned as it should be. Builders and house-owners should 

 understand it thoroughly, as most of the domestic miseries 

 resulting from severe winters may be greatly mitigated, if not 

 entirely prevented, by scientific adaptation in the course of 

 building construction. Nowadays tenants know something 

 about this, and select accordingly. Thus the market value of a 

 building may be increased by such adaptation. 



Solids, liquids, and gases expand as they are heated. This 

 great general law is, however, subject to a few exceptions, the 

 most remarkable of which is that presented by water. Let us 

 suppose a simple experiment. Imagine a thermometer tube 

 with its bulb and stem so filled with water that when the water 

 is heated nearly to its boiling point it will rise to nearly the 

 top of the long' stem. Now let us cool it. As the cooling 

 proceeds the w T ater will descend, and this descending will con- 

 tinue until it attains the temperature marked on our ordinary 

 thermometer as 39, or more strictly 39^; then a strange in- 

 version occurs. As the temperature falls below this, the water 

 rises gradually in the stem until the freezing point is reached. 



This expansion amounts to -^Vs" P ar ^ ^ ^ ne WD0 ^ e bulk ^ 

 the water, or 100,000 parts become 100,013. So far the 

 amount of expansion is very small, but this is only a foretaste 

 of what is coming. Lowering the temperature still further, 

 the water begins to freeze, and at the moment of freezing it 

 expands suddenly to an extent equalling -^ of its bulk, i.e. of 

 the bulk of so much water as becomes solidified. The temper- 

 ature remains at 32 until the whole of the water is frozen. 



