GENEBAL SCIENCE 



Why is 3-ply red rope waterproof paper used at C? 



Why is wool felt deafening paper used at Z)? 



Explain the use of flaxlinum insulation at E and F, dead air 

 spaces at E, 3-ply red rope waterproof paper at H, and the outside 

 wood case at I. 



FIG. 76. Section of a Refrigerator. FIG. 77. 



THERMOS BOTTLE 



Why is a cork stopper used? 



Why is. the bottle placed on a spring (two reasons)? 

 Why is a space left between the outer case and the bottle? 

 Why is the bottle made in two sections with a vacuum between 

 the inner and outer bottle? 



Why is the bottle made very shiny? 



QUESTIONS 



1. Why do soup companies use copper and nickel kettles? 



2. Why are flatiron handles made of wood? 



3. Why is ice packed in sawdust or straw? 



4. Why do late spring snows melt from stone walks more 

 quickly than from board walks? 



5. How does clothing keep us warm? 



6. Why are plants covered with paper at night to keep them 

 from freezing? 



