EXERCISE 10 A 



TO REPRESENT GRAPHICALLY THE RELATION OF CENTIGRADE AND 



FAHRENHEIT SCALES 



Materials. A sheet of cross-section paper (paper ruled in two directions at right angles) ; the 

 data from Exercise 10. 



Directions. On the accompanying sheet of cross-section paper, the heavy horizontal lines are 

 numbered to represent the Fahrenheit scale. The lowest heavy line represents 30, the next one 

 40, and so on to the top of the paper. Each light line thus represents one degree. Similarly the 

 vertical lines represent the centigrade scale. 



Place a point at the intersection of the line representing 212 F. with the line representing 

 100 C. This point represents the following relation : 



212 F. = 100 C. 

 Locate another point to represent the following : 



32 F. = C. 



Draw a straight line through these two points from one margin of the paper to the other. If accu- 

 rately constructed, this line may be used as a means of transferring readings from one scale to the 

 other. For instance, if the temperature of the room is 22 C., the Fahrenheit equivalent may be found 

 as follows : Follow the 22 C. line upward to its intersection with the diagonal line. From the point 

 of intersection follow the nearest horizontal line to the left side of the page and read off its value in 

 the Fahrenheit scale. Reverse the process to change from Fahrenheit to centigrade. 



Place on the page points to represent each pair of readings secured in the preceding exercise. 

 The distances by which they are separated from the diagonal line are due to inaccuracies in your 

 observations or in the thermometers. 



Preserve this sheet and use it to change temperature readings from one scale to the other. 



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