On the Theory and Practice of Water-Meadows. 467 



the united streams further. The conjoint river is unfit for water- 

 ing until it has received another stream of excellent quality near 

 to Bampton, after which it is capable of being used not alone, 

 indeed yet, but to assist in making up the volume of tributary 

 streams which are diverted along its banks. When the Exe 

 however, now a broad river^ has passed through the busy town 

 of Tiverton — every street of which has a running stream washing 

 away the ordure — the Exe becomes again fertilizings and mea- 

 dows are formed to receive its waters. The theory of irrigation 

 appears then to be this : — Water acts upon meadows by im- 

 parting its warmth to them ; perhaps also as a covering, by 

 enabling them to retain their own warmth. If the water contain 

 mud or fine soil its action is stronger. If the drainings of yards 

 or of towns, stronger still. On the other hand, the colder the 

 stream the less likely it is to act, and its powers are weakened 

 or destroyed by the presence of carbonic acid (by hardness), 

 or of iron, or of tannin. The quality of the fish has been seen 

 to indicate that of the water. A well-known herb, the watercress, 

 is said to be an unfailing witness for the goodness of the stream 

 along whose bottom it flourishes. 



We may now turn from the theory to the practice of irrigation. 

 Water-meadows are formed on two systems. In the southern 

 counties, Hampshire, Berks, Wilts, Gloucester, and Dorset, the 

 Itchin, the Kennet, the Avon, and other rivers, are diverted ; and 

 the neighbouring land being flat is entirely reshaped to receive 

 them. The turf is pared. The whole surface is laid up in high 

 regular ridges, about thirty feet wide, along whose summit the 

 water runs in gutters, overflowing the sides to the bottom, where 

 other gutters receive them and carry them off. In form the 

 meadows are like the sea after a storm, when the long waves are 

 subsiding. 



Plan of Water-Meadow. 



Section of Water-Meadow 



A . Dam across river. 

 d. Diaining Gutters. 



B. Main Carrier. c. Watering Gutters 



E. Main Draining Gutter. 



