A SLICE OF ICE

Place the block of ice on the board and drape the wire across the top as shown in the drawing.The ice just beneath the wire will melt because of the pressure exerted by the wire. The melted ice above the wire then refreezes, trapping the downward-moving wire inside the ice. 

After a few min utes, the wire will have passed all the way through the ice block. Once that has happened, knock the ice with a hammer and see where it breaks. (In the days before refrigerators, this was the way large ice blocks were cut to size for the kitchen icebox.) 

What do you suppose would happen if string were used instead of wire  

Ice is slippery because its crystalline structure is not easily maintained at the surface. 

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