HEAT 



83 



one to express his individual opinion, and to ask his own ques- 

 tions. Do not by your conduct with the class put a premium so 

 much on any kind of answers, even bright ones, as on earnett 

 questions and answers. Give all such, even if apparently ignor- 

 ant and far from right, every con- 

 sideration. Children, like other 

 people, are sensitive in regard to 

 the respect given to their opinions. 

 Nothing with them is so inimical 

 to the independent formation of 

 opinion as to have their opinions 

 treated with disrespect. If one 

 is wrong, prove that he is wrong, 

 but neither ridicule him nor ride 

 over him. Avoid allowing a few 

 to lead the 

 class and set 

 opinions for 

 the rest. 



Heat Ex- 

 pands Air — 



Use the 

 flask and tube 

 of the experi- 

 ment of heat 

 expanding 

 water. Have 

 the flask clean 

 and dry. Place 

 the end of the 

 tube under 

 water. Warm 



i*lg. &4. iixpaasion of air by heal. 



