112 AS TO SERVICES AND METERS 



the settings as far as possible so that if the meter first installed 

 proved to be too large or too small, another size could be readily 

 substituted for it without undue disturbance of conditions. 



In some cities the use of meters in batteries is common; 

 that is to say, a considerable number of meters, perhaps 2 inches 

 in size, are set in parallel and as many of them are connected all 

 the time as the business requires. This has the advantage that 

 the meters can be taken out in detail for inspection and repair 

 without disturbing the service. 



John Thomson, whose wide experience as a designer and 

 maker of meters qualified him to speak with authority, stated : * 



Probably three-fourths of the meters in public use to-day are con- 

 siderably underworked; that is, if proper judgment could be depended 

 upon in selecting the capacity of the meter to do the duty to be performed, 

 still more compact and less expensive nominal sizes might be the result. 



The opinion then expressed has been but strengthened by experience 

 meantime gained ; and while there is no more exasperating and inexcusable 

 fault than to set a meter so as to be damaged by over-running, a fault 

 promptly made evident, but little is ever said or known regarding the oppo- 

 site condition, that is, under-running, which prevails to a much larger extent 

 than is generally supposed. The reason for the latter is probably too often 

 due to the greater convenience of measuring the diameter of the pipe, 

 to which the contemplated attachment is to be made, rather than measuring 

 the quantity which the pipe can deliver. 



The writer believes that there is but one reliable and satisfactory 

 method for practically determining the proper maximum capacity of a meter 

 to be applied to a service, namely, to insert a meter in circuit, open all the 

 valves or faucets and time the operation of the meter for one, five or ten 

 minutes. Thus, if a f-inch meter has been set and its full delivery is only, 

 say, i cubic feet a minute, then in the majority of cases a f-inch meter 

 would satisfactorily replace it and so on through the range of sizes. 



The Committee on Meter Rates examined its statistics to 

 ascertain how much water was ordinarily passed by meters of 

 different sizes. This study rested on the fundamental assump- 

 tion that the largest meter in any system supplies that service 

 in the system from which most water is drawn ; and that all the 

 other services are to be assigned to the meters of the several 

 sizes in the order of their outputs. This is not strictly correct, 



* Jour. N.E.W.W. Assn., Vol. VIII, 1894, p. 63. 



