Measurement and Division of Water. 15 
of water which he receives. A cleat of some kind is often used 
to prevent the board from being moved beyond a certain limit. 
Where the ditch is wide and shallow there is sometimes a simple 
truss used, with a "depending cleat. Sometimes a wire or chain 
restricts the movement. In these cases it is assumed that the amount 
of water going to the side channel is in proportion to the distance 
the movable partition is from the side, and the ratio is the same to 
the distance across as the volume is to the volume in the whole 
ditch. This is not, in general, true, because the velocity across the 
cross-section is not uniform. 
Sometimes where this is recognized, and it is necessary to 
make close division, the water is brought to a state of approximate 
rest, or to a state of approximate equal velocity throughout the 
channel. In the case of some divisors, as in one seen on the 
Farmers’ Union Ditch, in the San Luis valley, a weir-board over 
which the water drops is placed above the division board. This 
secures an approximate equality. The fall below the point of 
division should be sufficient to prevent the backing up of the 
water. 
If water is brought to a complete state of rest, or very nearly 
so, and flows over the weir without lateral contraction, this method 
will give as satisfactory results as any divisor with which I am 
acquainted. An increase in the size of the ditch just at the division 
box will aid in bringing the water to rest. Boxes of this kind 
were used by Hon. J. Max Clark, of Greeley, as early as 1867. 
The divisor which is in use at Elche, in Spain, is one which 
has developed from their conditions in that province. At Elche 
there is a peculiar system of water management. The water is 
owned independently of the land. The amount available is divided 
into a certain number of shares, and the use of each of these for 
twenty-four hours is sold each day in the market place to those who 
want water. In consequence the amount which enters any lateral 
varies from day to day, and'the method of division requires a con¬ 
venient way of varying the proportion. 
Where the division is to be made, the sides and bottom of the 
canal are made of cut stone for a distance of about fifteen feet. 
There are two falls in the canal of twelve to sixteen inches respec¬ 
tively, about five feet apart, the upper one being about seven feet 
from the upper portion of the masonry. The canal for a distance 
of 150 to 200 feet above has little or no fall, so that the water 
reaches the first fall with almost no velocity, and passes over 
undisturbed and perfectly smooth. Furthermore, there is no con¬ 
traction at the ends, so that the discharge is nearly in proportion 
to the length. 
The arrangement for making the division consists of a parti- 
