30 FIRST YEAR COURSE IN GENERAL SCIENCE 



center of - ? (Use a measure and compute from the 

 scale on the map.) 



(7) Does the River cross any contour lines 

 between - - and - ? 



(8) Does the highway? The railroad? 



(9) What do your answers show in regard to the elevation 

 of these two places? 



(10) Why are roads more likely to follow than to cross 

 contour lines? 



(11) What is the significance of the straight lines crossing 

 the map from north to south? 



(12) How much of the surface of the earth is included in 

 this map? (Answer in degrees or parts of a degree.) 



EXERCISE XXII (Textbook 259) 

 STUDY OF A STREAM AND ITS VALLEY 



PLACE OF WORK: Any locality where a stream, prefer- 

 ably a brook, can be studied for a length of half a mile or so. 

 (A teacher can usually indicate an accessible stream and 

 perhaps accompany the class to visit it.) 



DIRECTIONS FOR WORK: Begin at the lower end of the 

 portion of the stream selected (at the mouth, if possible), 

 and make notes on the following points: 



(1) The direction and velocity of the current. 



(2) The character of the banks, whether alike in material 

 and form on both sides. 



(3) Evidences of erosion or deposit. 



(4) Signs which tell of higher water earlier in the season. 

 Follow the stream toward its source, observing any 



changes in any of the respects observed.. 



(5) Is the course of the stream straight or wandering? 



(6) Is its valley broad or narrow? 



(7) Has it any tributaries? 



(8) Are there rapids or falls at any place? 



