UNACCOUNTED-FOR GAS. 



CHAPTER XI. 



UNACCOUNTED-FOR GAS. 



THIS subject is taken separately, as being an important 

 matter that is frequently a source of trouble and anxiety. 

 There are several reasons why a small undertaking cannot 

 expect to reach the limits that are practicable in large 

 towns. It is usual to express the loss as a percentage of 

 the total output. While this is convenient for statistical 

 purposes, it is apt to be misleading when applied to technical 

 considerations, because the connection between quantity 

 used and quantity lost is extremely remote. Frequently 

 one hears that the leakage has been reduced, when, as a 

 matter of fact, it remains exactly the same. One year the 

 output may be 3,000,000 cubic feet, and the unaccounted- 

 for 500,000 cubic feet, or 16 per cent. The next year the 

 output is, say, 4,000,000 cubic feet, and the unaccounted- 

 for remains as before, but is now 12^ per cent. It is 

 misleading to say that the unaccounted-for gas has been 

 substantially reduced. Matters that directly affect the loss 

 are extravagance at the works, waste or excess of schedule 

 quantity for the public lighting, mileage of mains, number 

 of services and meters, and the percentage of meters that 

 show a consumption of less than 1,000 cubic feet per 

 quarter. 



But there is too great a tendency to suppose that a loss 

 of 15 to 20 per cent, must be accepted as unavoidable. 



