WHAT WE KNOW ABOUT AIR 



Courtesy Taylor Instrument Company 

 FIG. 4. ANEROID BAROMETER 



In your notebook 1 write a clear statement of what was 

 done. Under the heading, "Observations and Inferences," 

 complete the following statements. The dial of the aneroid 

 was marked off in and The air gets to the work- 

 ing parts of the aneroid through . The little box in the 



center has a surface. The words , , and 



are printed on the dial of the barometer. The word 



seems to be associated with a low barometer reading. The 



word seems to be associated with a high barometer 



reading. The aneroid barometer read when I made this 



A-Chdm. B- Pointer 



FIG. 5. WORKING PARTS OF THE ANEROID BAROMETER 



observation. The barometer may be set for future read- 

 ings by -- From my observations I would conclude that 

 the uses of the aneroid barometer are _ 



OTHER INVESTIGATIONS WHICH YOU CAN MAKE 

 Carry an aneroid barometer from the bottom of a hill 

 to the top and note any change in the reading. Infer a cause 

 for this. 



READINGS WHICH WILL HELP ANSWER THE 

 PROBLEM QUESTIONS 



What is known about the nature of air and the 

 atmosphere? Air is a colorless and odorless mixture 

 principally made up of the two gases, oxygen and 

 nitrogen. Because it is ever present and because we 

 walk through it with ease, we are usually reminded 

 of its presence only as we walk against a strong wind 

 or see the destruction which moving air has caused 

 in a tornado or other wind storm. We ride on cush- 



ions of air in our automobiles and bicycles and 

 through the air in airplanes and dirigibles. Air-driven 

 machines aid in quarrying rock, mining coal, erecting 

 great buildings, and tunneling under the earth's sur- 

 face for subways and railroads. Most important of 

 all, animals need oxygen from the air to keep them 

 alive. 



It is a familiar experience that water, oil, or other 

 'liquids will not run out of bottles or other containers 

 unless air bubbles in to take the place of the liquid. 

 If you have ever drawn a cup of water from the large 

 inverted water bottles commonly found in office build- 

 ings or if you have attempted to drink water from a 

 bottle, you know that as the water comes out air 

 bubbles may be seen going up through the water in 

 the bottle. 



The earth is surrounded by a blanket of air which 

 is known to be more than twenty miles in depth. This 



-22- 



MILtS 



-21- 



-20- 



|Q . 



-18- 

 -17- 

 16- 

 15- 

 14- 

 13- 

 -12- 

 II- 

 10- 



-8 

 -7 

 -6 

 -5 

 4- 

 -3- 

 -2- 



Highest sounding 

 balloon 

 22 mi. 



^ Soviet 

 11.4 mi. 



Soucek 

 8.1 mi. 



Cirrus clouds 

 above 7 mi. Mf Everest 



Stevens and 



Anderson 



13.7 mi 



Settle and Fordney 

 . 11.6 mi. 



I Piccard 

 10 mi. 



Doiuti 



8.9 mi. Base of 

 stratosphere 



\ Coxwell 

 ' 7 mi. 



clouds 

 about 5 mi. 



/Pv^^c-Qi- , 



1 Sec accompanying workbook, t>. 4. 



FIG. 6. MAN'S EXPLORATION OF THE STRATOSPHERE 



