HEAT CAUSES EXPANSION 



45 



a. Arrange appara- 

 tus as shown. Light the 

 candle and immediate- 

 ly mark the position of 

 the end of the wire. 

 Watch it and tell what 

 happens. What causes 

 the change? Blow out 

 the candle and explain 

 what happens. 



b. Bore a hole in 

 the cork stopper so 

 that the glass tube will 

 fit it snugly. Push the 

 tube into the hole so 

 that the end is even 

 with the inner side of 



the stopper, and insert the stopper tightly into 

 the bottle. Place the other end in a tumbler of 

 water. Warm the bottle with the hands, while 

 watching the end of the tube which is under 

 water. What happens? Why? Now warm 

 the bottle gently with a flame? What occurs? 

 Allow the bottle to cool. What do you see ? 

 Why? As the air cooled it contracted thus 

 occupying less room, or space. The surface of 

 the water in the tube merely fits against the air. 



