LABORATORY MANUAL 21 



Connect by light straight lines the successive points 

 indicating maximum temperatures, and by another set of 

 lines the minimum temperatures. 



The official record of maximum and minimum tempera- 

 tures may be obtained on application to the local office of 

 the Weather Bureau. If secured, make another set of 

 records and lines, and compare with your records. 



RESULTS 



NOTE. Such a series of lines as you have made is called 

 by scientists a curve. The range of temperature is the differ- 

 ence between the highest and lowest temperatures of a 

 period. 



1. What is the highest reading recorded by the tempera- 

 ture curve? The lowest? 



2. Are the variations from day to day alike? 



3. What was the range of temperature for the period of 

 observations? 



4. What was the greatest daily range? Give date. 



5. What was the least daily range? Give date. 



6. What was the highest average temperature? Give 

 date. 



7. What was the lowest average temperature? Give 

 date. 



EXERCISE XIV (Textbook 142) 

 THE SIMPLE ELECTRIC CELL 



APPARATUS: A small strip of copper, a strip of zinc, 

 insulated copper wire, binding screws, compass, tumbler of 

 water containing a little acid (about 1 part acid to 12 parts 

 water) . 



DIRECTIONS FOR WORK: Caution: Sulphuric acid, which 

 is heavier than water, should always be poured into the 

 water; never pour the water upon the acid. In the latter 



