Fill a common bottle with coloured water; insert a rubber stopper through which passes a glass tube about sixteen inches long. Set the bottle in a pan of water and gradually warm the water. The rise of the liquid in the tube will indicate expansion. On setting the bottle in cold water the fall of the column of coloured water shows contraction. See The Ontario High School Physics, page 218, also Science of Common Life, page 48. Macmillan Co., 60 cents.
Set the flask or bottle in a mixture of ice and salt and note that the extreme cold causes contraction for a while, then expansion. Note that when expansion begins, the water has not begun to freeze, but that it does so soon after.
The night before this experiment the children should set out in the cold air, tightly corked bottles of water. In the morning they will be found burst by the expansion.
APPLICATIONS
1. Why did some of the ink-bottles burst in the cold room?
2. Find large stones split up into two or more fragments. Explain.
3. Why is fall-ploughed land so mellow in spring?
4. Why does ice float? Think what would happen if it did not.
5. Explain the heaving of oats, clover, wheat.
6. Do all liquids expand on freezing? Try melted paraffin.