178 Journal of Agriculture. [10 March, 1909^ 



These headvvorks are small but massive masonry structures, each with two sliding, 

 gates of sizes — proportioned to their rights — from 3^ to 7 feet in width. To each 

 headwork is a dam of masonry across the river channel, whose crest and length of 

 overfall is so regulated, with respect to the elevation and width of the sill of the 

 canal gates, as approximately, to divert the proper proportion of the waters into the 

 canal without the necessity of manipulating the gates for every small variation in 

 the river's flow 



" All these weirs date from the time of the Moors, and nothing is certainly known 

 as to their foundation, but tradition says that the solid masonry is carried down 

 13 to 17 feet below the river bed, and that it rests upon piles, the heads of which 

 are embedded in masonry." — (Aymard, p. 20.) 



Interesting details follow as to the apporlionment of water which is- 

 often made — 



In terms of a unit of measure whose real volume is indefinite. This unit is 



called a " thread of water," and the volume of the stream when all in use is 



divided into 13S " threads," each canal taking its proportionate part of the whole 

 according to a fixed schedule. 



This system was frequently followed in other parts of Spain as well as in- 

 Algeria. 



By this system of proportionality each one enjoys abundance of water or suffers 

 from scarcity in the ratio of his interest to the whole. — (Aymard, pp. 24-25.) 



This, however, was over 40 years ago and Mr. Hall goes on to say 

 that — 



there were even then many irrigation works throughout other parts of the country, 

 which were due to the modern Spaniards, and where water was divided by measure- 

 ments of volume. 



Mr. Hall then deals with Irrigation legislation and administration. 

 He quotes Mr. Scott Moncrieff, who considers the latter — 



"to be well worthy of study. Here more than in France or Italy, government by 

 a representative Assembly is fully carried out, and has been for more than 600 

 years, with the best results." — (Moncrieff, p. 136.) 



Full particulars of curious local systems of administration and control 

 are given at length — Tribunal of waters, syndic labourers, &c. These- 

 extracts will suffice to show the efficiency of irrigation in this part of Spain. 



Concerning the district of Jucar, im.mediately south of Valencia, he 

 writes — 



The Jucar River, like the Turia, rises in the Sierra Molino Mountains, and 

 . . . waters the district immediately south of the Huerta de Valencia, making 

 with it and the district of Murviedro (now called Sagunto), immediately on the north 

 a continuously irrigated garden land near 40 miles in length. The Royal Jucar 

 Canal . . . has a length of about 26 miles. . . . The very massive dam, 

 headworks, legulating gates, and main outlet structures are all of cut stone masonry, 

 and the gates are generally moved by screws. The area of irrigation is about 

 50,000 acres, the cultivation is principally that of rice, the waters are often used 

 over the third time, and the system is so perfect that but little waste is suffered, 

 but the supply of water is abundant and the use extravagant. 



It will no doubt come as a surprise to many to know that to a certain 

 extent our own water laws are based on those of Spain. Mr. Stuart 

 Murray, late Chief Engineer of Victorian Water Supply, in reply to 

 some queries as to whether there were not some references to Spanish 

 irrigation methods in the reports published some years ago by the Water 

 Supply Department writes — 



I do not think there is any report issued by the Water Supply Department 

 containing direct reference to irrigation in Spain; at all events any reference that 

 would be likely to be useful for your purpose. There are references to the 

 Spanish law affecting rights in water and to the administration of the law in 

 Spain. . . . Part II., sections 4-24 of the existing Victorian law. Water Act 

 1905, is based, in great measure, on the Spanish Law of Waters; although of 

 course, no reference appears either in the text or marginal notes. 



