cally. 'These are of uniform width. They are held in place 
both in top and bottom, and are carefully fitted to prevent 
leakage. The stream is to be divided so that a certain num¬ 
ber of hilas, according to the result of the sale, may enter the 
channel. No account is taken of the difference introduced 
by contraction. The discharge is assumed to be proportional 
to the size of the opening. I have seen a divisor involving 
the same principle used on a ditch carrying seepage water, 
near Greeley. The form is not so good as the Elche divisor. 
DISTRIBUTION BY TIME. 
On small ditches or laterals where the amount of water 
is not too great for one user to manage, the time method of 
division may be used and gives a more equitable division 
than the boxes of the types described, and besides, it accom¬ 
plishes what is necessary in order to use water economically, 
it allows of the use of water in large enough quantities during 
irrigation to make the use much more economical than where 
used in minute quantities. If water is divided according to 
the various interests involved, so that each would receive 
constantly the amount to which he is entitled, and no more, 
it would often happen that the division would be into such 
small parts that little good would be done by the small stream 
of water thus furnished. It thus becomes necessary in almost 
all localities to exchange water between neighboring users, so 
that one will use the privileges of several for the time during 
which he is irrigating, and then the others in like manner 
will use the water of their neighbor whom they have already 
accommodated. The time method of division carries this 
exchange of water to a greater extent and is especially ap¬ 
plicable to the small ditches where the amount of water is 
small. In such case the exchange is systematized, and each 
one takes the whole stream of water for a time proportionate 
to his interests in the ditch, and the period is so arranged 
that the rotation will be completed in some definite time, as a 
week or two weeks, or such other time as the experience of 
the locality has shown to be desirable for an irrigation to be 
repeated. The water will then be given out at night or day 
according to a schedule, and in order that the inconveniences 
may be fairly distributed, the period of rotation may be made 
with a fractional day, so that those who came in the night 
during the first rotation will come in the day during the sec¬ 
ond, and vice versa. Thus, suppose the period of rotation be 
taken as one week, or for reasons above given, 7^ days, and 
the number of shares be fifteen, of which some own one, 
others two, and some three shares. In this case each share 
