as they cool, when water turns into ice it expands instead of shrinking, 

 and therefore the ice must ])0 less dense than the water. Now, any 

 solid that is less dense than Avater will float on water, and so we see 

 why ice always floats on water instead of sinking. Try this for your- 

 self with a lump of ice and a tumbler of water. Try and judge how 

 much of the ice is above the water and how much below. If you can 

 judge Ycry accurately you will find that there are about eleven times 

 as much of it below as above. 



How many different effects produced by this expansion of freezing 

 water can you think of? Thei'e are some very important ones, indeed; 

 but we must ]i';i\c sncb i(iiestions as thi^si' for another leaflet. 



