The Colorado Statute Inch 
13 
different kinds of measuring devices used in connection with underground 
pipe systems, but only one was experimented with. 
The Azusa hydrant is used in the vicinity of Azusa, California. The 
essential features are shown in figure 3, and the details of the orifices 
are shown in figure 4. It consists of a concrete box about 6 feet high 
placed in the supply pipe line, with the orifice plate set in the side of 
the box so the tops of the orifices are 12 inches below the top of the box. 
An overflow crest placed on the top of a dividing wall in the box is 2 
inches above the top of the orifices. The flow through the orifices is reg¬ 
ulated by a gate in the dividing wall near the floor. There are 4 orifices 
each 4 inches deep and of different widths which are supposed to deliv¬ 
er 10, 15, 25 and 50 miner’s inches upon the basis of 50 miner’s inches 
to 1 second foot and they may be used singly or in a combination. The 
orifice plate is made of cast iron carefully machined. 
The results of the experiments with the Azusa hydrant given in table 
5, indicate the actual discharges to be from 2.0 to 6.4 percent less than 
the intended discharges. Table 6 gives the dimensions of orifices which 
will discharge the intended number of miner’s inches. However, in actual 
practice the orifices become larger, due to the edges rusting, and the 
head of water is usually greater than 2 inches because a small amount 
is allowed to pass over the spillway or overflow. 
In Bulletin 247 of the California Bxpkeriment Station, Mr. Prank 
Adams states the cost of the Azusa hydrant to be from $18 to $20 under 
a large contract, and about $30 when built singly. The orifice plate costs 
an additional $12. 
