HOW DO WE BREATHE? 



77 



(2) What happens to 

 the human diaphragm 

 when the ribs are lowered ? 



(3) What causes air to 

 come into the lungs? 



(4) What causes air to 

 pass out of the lungs? 



The chart and appara- 

 tus should be presented to 

 the science department of 

 the school for class use 

 after the meeting. It will 

 be valuable for class dem- 

 onstrations. 



..cardbooret 

 -brass -fastener 



atrctboccrcC strip 



...papci 



7. How TO MAKE A BATTERY JAR FROM A BOTTLE 



Cut the top off a large glass bottle or jar one quart or one 

 gallon the larger better. Make a deep file scratch where you 

 wish to cut it. Heat a heavy metal soldering iron or curling 

 tongs red hot and press upon the scratched glass. After a crack 

 is started, keep applying the red hot metal just a little ahead of 

 the crack and it will follow it around. Another method is to wet 

 a cotton string with kerosene. Wind two or three layers around 

 the bottle and tie. Set fire to the string, holding the bottle hori- 

 zontally and turning slowly. When fire goes out, wet the bottle. 

 This jar will be very useful in many experiments. 



REFERENCE READING 



Archibald, D., The Story of the Earth's Atmosphere. Appleton, 



1915. 



Compton's Pictured Encyclopedia. 



Houston, E. T., The Wonderbook of the Atmosphere. Stokes Co. 

 Meister, M., Water and Air. Scribner's, 1930. 

 Talman, C. F., The Realm of the Air. Bobbs-Merrill, 1931. 



