FOR LARGE METERS 



87 



areas computed from these diameters do give something of an 

 idea of the relative capacities. 



The relative carrying capacities of disc meters at a fixed 

 loss of head, as given in the American Civil Engineers' Pocket 

 Book, page 967, may be used. It is of course understood that 

 different makes of meters vary a good deal in their capacities. 

 The figures mentioned were compiled by the chairman of this 

 Committee some years ago, after receiving returns from various 

 manufacturers of meters and examining records of experiments 

 by a number of members of the association, and they were selected 

 as being representative of the different sizes. Round figures 

 were used, and they are to be taken as a general indication only. 



The maximum normal amount of water supplied by each size, 

 as deduced by this Committee from the returns made to it in the 

 inquiry with reference to waste prevention, may also be used. 

 The figures obtained in this way represent only a limited amount 

 of data, but that is the best of its kind now available to the 

 Committee. There are some irregularities in the scale. For 

 instance, 2- and 4-inch meters are distinctly more popular and 

 are used in larger relative numbers than some of the inter- 

 mediate sizes, and in fixing the normal capacity of meters the 

 influence of the tendency must be discounted to reach the fair 

 relative capacities. 



The relative capacities of meters of several sizes calculated 

 in each of these three ways, taking the capacity of a 2 -inch 

 meter as ten in each case, are as follows: 



