78 LABORATORY EXERCISES 



EXERCISE 74 

 GAS. AND ELECTRIC METERS 



Apparatus. Home meters for gas and electricity, fuse box. 



a. On the left half of a page of your note book make 5 neat 

 pencil copies of the gas meter shown in Fig. 212, ?56, of the 

 text. Do not, however, put in the "hands" of the meters until 

 they are called for. On your first drawing put in the hands 

 just as you find them on your home meter. If the upper circle 

 of your meter is intended to read only to 2 cu. ft., change your 

 drawings accordingly. On the right half of the page, opposite 

 the first meter, write down in figures the reading of the meter 

 and the date on which the reading was made. 



6. Exactly one week after the first reading take a second 

 one, putting in the hands of your second drawing. Opposite 

 the drawing put in the date, the reading, and the difference 

 between the first and second readings. Continue making the 

 readings for 4 weeks. 



What was the total gas consumption for the 4 weeks? 

 What was the average for a week? What was the cost of the 

 gas for the 4 weeks? 



c. Find the key or lever by which the gas supply can be cut 

 off so that it cannot go through the meter. How could you 

 prevent gas from escaping if a pipe should burst somewhere in 

 the house? 



d. In the same way as in a, but on another page, draw 5 copies 

 of the kilowatt-hour meter. See Fig. 215, 259, of the text. 

 Take 5 readings, just a week apart, and mark the positions of the 

 hands on the dials. Date each drawing, write down the readings 

 in figures, and give the differences between successive readings. 



How much electric energy did your family use each week? 

 What was the total? The average for a week? What was the 

 total cost? 



