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GENERAL SCIENCE 



made for the purpose; no air can get into the ovens. 

 The gas that comes from the heated coal is forced through 

 water and various substances which remove all the solid 

 matter and other undesirable elements. The pure gas is 

 then forced into storage tanks from which it is piped to 

 buildings for the same uses as natural gas. 



George Westinghouse invented a convenient device 

 for measuring the gas as each customer burns it. This 

 operates much like the apparatus in the steam chest and 

 cylinder on an engine. The gas meter is composed of a 

 metal case divided into two parts by a movable dia- 

 phragm, and a clockwork device records the move- 

 ments of this diaphragm. When the gas flows into one 

 side of the meter the diaphragm is forced over and the 

 gas on the other side is forced out to the burners; when 

 one side of the meter is full of gas the entrance valve 

 closes and the entrance valve of the other side opens, 

 and through this the gas enters and forces the diaphragm 



to the opposite side and 

 the gas of that side flows 

 out to the burners. 

 The movements of the 

 diaphragm are recorded 

 by the dials on the gas 

 meter. 



Gas is measured by 

 the cubic foot and is 

 paid for by the thousand 

 cubic feet. Every person who uses gas should know how 

 to read a meter. A meter with four dials will give four 

 digits, to the right of which we add two ciphers, thus, 

 263,800. (Provided the four dials are all in a row.) 

 To read one of the dials we take the smaller of the 



INDEX OF A GAS METER 



