566 EVERYDAY SCIENCE 



To offset this cause of confusion, it is well to remember that in 

 such sections underbrush and small plants grow more densely on a 

 northern exposure than on a southern exposure, because the sun 

 does not get a chance to dry out the north slope so thoroughly. 

 The practiced guide knows too that mosses grow where they can 

 have not only shade but an abundance of moisture. The prevail- 

 ing winds, therefore, may have something to do with local variation 

 of moss growths. 



If you are near a forest, make a study of conditions that prevail 

 there and report on them to the class. Take your compass with 

 you. Find out on which side of trees the moss growths usually 

 occur. If not on the north side at all times, see if you can offer a 

 reason for the variation. Study the vegetation and soil on all slopes, 

 if you are in a hilly or mountainous region, and report the results 

 of your observations. 



If you will be constantly on the alert, in whatever sections 

 you traverse, you will eventually accumulate much valuable forest 

 lore. 



PROJECT III. How a Boy Scout Determines Latitude by the North 

 Star, page 32 



Choose a straight post or tree from which the North Star may be 

 sighted. Nail a smooth piece of board, about a foot square, to the 

 east or west side of the post or tree so that you can sight the North 

 Star along the face of the board. 



Drive a six-penny or eight-penny wire nail straight and securely 

 into the upper north corner of the face of the board (K), and sus- 

 pend a plumb line from the nail (KL) . Now from the south edge 

 of the board, sight along the face of it until you can see the North 

 Star immediately under the wire nail. Then move the point of a 

 knife, or scratch-awl, along the face of the board near your eye until 

 you can just sight the North Star over the edge of the blade. When 

 the knife reaches this spot, stick the point of the knife-blade care- 

 fully into the board. If you have sighted accurately, the star can 

 be seen just under the nail and over the knife blade. If the eye 



