AMOUNT OF HEAT FROM THE SUN 41 



sun, while the "surface of the earth" is parallel with the 

 real surface of the earth. The best way to do this is to 

 place the arm in such a position that the sun shines 

 through the hole in the bent end. and falls lengthwise 

 along the middle of the strip. Read the angle on the 

 protractor. This is the elevation of the sun. Count the 

 number of spaces covere'd by the ''sunbeam." How 

 strong is the sunlight compared with what it would be 

 if it were perpendicular to the "surface of the earth?" 

 Remember your buttered bread ! 



c. Repeat (b.) at noon. What is the elevation of 

 the sun? How many spaces are covered by the "sun- 

 beam"? How strong is the sunlight compared with what 

 it was early in the day? 



d. Take a reading once a week, of the sun at noon 

 and the number of spaces covered by the "sunbeam." 

 Continue this experiment the rest of the year. Keep a 

 record and compare it with the record which you are 

 keeping of Experiment 10 



The amount of heat which is taken up by different 

 objects is very different, although all of the objects may 

 be near one another in the sunshine. Shiny objects do 

 not become very warm in the sunshine. What is the 

 effect of shiny objects upon light? They do the same 

 thing to heat and therefore they do not become warm. 

 White objects and those having light colors also are 

 quite cool in the sunshine, but are warmer than the 

 shiny objects because they do not reflect so much heat. 

 Dark colored and rough objects reflect very little heat 



