8 The: Colorado Experiment Station. 
in the distribution and measurement, are the same. We are find¬ 
ing certain laws and regulations to be necessary which they found 
to be necessary centuries ago. They have outgrown their first 
crude methods. One of their most widely used modules was based 
upon an erroneous idea. It was early introduced into Colorado and 
used on some of the earlier ditches. 
The need for measurement dates back to the beginning of 
irrigation. The methods were necessarily adopted without much 
hydraulic knowledge. That they were fairly satisfactory, reflects 
credit upon those who had to make them. This is especially true 
in regard to the well-known Milanese module produced by Soldati, 
and adopted by the magistrates of Milan. But we find fairly work¬ 
able methods, crude to be sure, but adapted to the conditions, among 
the ancient Romans, among the Moors, and among almost all users 
of all nations who have tried to make a fair division of a fluctuating 
quantity. The modern Italian canals, like the Cavour Canal, 
the Canale Casale, Canale Villoresi, have adopted methods of 
measurement depending upon the weir. While the old mea¬ 
suring box or module is still used on the ancient canals of 
Lombardy, it has had to be modified to meet modern condi¬ 
tions. Other provinces or coommunities have generally other 
methods. In some cases users have acquired rights under a 
particular manner of measurement. They are afraid of any 
change for it may affect their rights and thus arouses intense 
opposition. Soldati met with so many difficulties in the attempts 
to reform the system of measurement and with such violent abuse 
that he met the fate of the reformer who attempts to change the 
settled customs of a people. This may be, and often is, a kind of 
conservatism but becomes a violent opposition among those who 
think they are affected. The same kind of conservatism is shown 
in Colorado. Ar he same varied customs which gave rise to the 
abuses in Italy which Soldati tried to check are becoming fixed. 
There are numerous canals in which there are different classes of 
users. Their rights are different. Water is measured to them in 
different manners, or at least on a different basis. This intro¬ 
duces problems of measurement much more complicated, but not 
different in kind, and sometimes makes a difference in the method 
required. Thus, as an illustration, one canal which may be taken 
as fairly typical indicates the character of the questions of measure¬ 
ment which arise. That canal includes the following classes of 
rights: 
1. What may be termed as preferred rights. A number of users 
entitled to unlimited water without measurement and without assessment. 
These are due to special contracts whose origin generally lie in the fact 
that the canal has been the successor of an earlier ditch and the users 
in the earlier ditch have relinquished their ownership for this consid¬ 
eration. 
