GAS AS A FUEL 153 



heater is in operation. The pilot-flame gas for these heaters would 

 amount to one-tenth of a cent per hour. Room heaters require 

 5 to 10 cents worth of gas per hour. 



Since a match costs only one-tenth mill or less, it is usually eco- 

 nomical to turn off the gas when not in use, except for short intervals. 



Error of Gas Meters. Gas meters may be slow or fast. Gas 

 companies are allowed to have gas meters in operation from 1 to 3 

 per cent slow or fast, since any measuring instrument of this charac- 

 ter cannot be absolutely correct. This allowance is called a toler- 

 ance. Meters of well-conducted companies are usually within this 

 tolerance, but it does happen that serious errors occur in gas meters, 

 especially in districts where there are no inspectors. A consumer 

 should check up his meter occasionally. He should read his meter 

 as nearly as possible at the time when it is read by the gas company, 

 and check the consumption with the gas bill, to prevent errors which 

 may occur in the office of the company. 



Leaks cause a great loss of gas at times. The consumer may 

 check his meter by turning out all gas consuming appliances and 

 watching the test dial for several minutes. If there is a leak the 

 dial will register and the amount of gas lost per hour or day may be 

 computed. 



If a consumer's bill for a certain period of time greatly exceeds 

 that of a previous period, it is due to one or more of the following 

 causes: 



1. An increase of gas consumption; 



2. An error of the gas company in reading the meter; 



3. An error in the office work; 



4. A fast meter; 



5. A leak. 



Tubular Connections for Gas Fixtures. Leaks are often caused 

 by poor connecting hose or gas tubular connections. Sometimes 

 the connecting hose is made of paper covered with cloth. If the gas 

 is turned off at the gas appliance to which such a tubing is connected, 

 a small amount of the gas will continually escape. Such a tubing 

 may be easily broken or ruptured and a considerable amount of 

 gas escape through a small opening. 



