LABORATORY MANUAL 29 



2. The elevation of the third section line? 



3. By what contour lines are these elevations represented? 



4. What is the elevation of contour line a? Contour line cf 



5. Compare the area of the base of the object with that of 

 the other sections. 



6. Which of your drawings represents this comparison? 



7. If an insect crawled by the shortest line up the side of 

 the object you have studied, what line on the profile would 

 represent his path? 



8. How would his path be represented on the contour 

 lines? 



EXERCISE XXI (Textbook 243) 

 STUDY OF A TOPOGRAPHIC MAP 



MATERIALS : A sheet of a topographic map of the region 

 in which you live. (Such maps are made by the U. S. 

 Geological Survey in connection with the state. They can 

 be procured at ten cents each, cash or money order, from 

 the Director U. S. G. S., Washington, D. C.) 



DIRECTIONS FOR WORK: Select a portion of the map in 

 which there are streams, highways, railroads, and two 

 towns a few miles apart. (Choose the portion that is most 

 familiar to you.) Note the horizontal scale as indicated at 

 the bottom of the map. 



(1) What is the meaning of white areas on a topographic 

 map? 



(2) What is the meaning of few contour lines to the inch? 



(3) How would you describe a region where contour lines 

 were near together? 



(4) A road crosses contour lines; how can you tell whether 

 it is up hill or down? 



(5) Find an up-hill road on the east side of the 



River. Locate it. 



(6) How many miles is it from the center of to the 



