1835.] 



FARMERS' REGISTER 



349 



out taking into oonsideration the deposition to be 

 obtained from all water however apparently pure, 

 or that decomposition of its elements which it un- 

 dergoes. 



Many errors still prevail in regr.nl to irrigation, 

 which have a tendency to raise a prejudice against 

 the system itself,- from the disappointments those 

 have felt who have proceeded upon wrong princi- 

 ples, either in the original formation of their mea- 

 dows or in their subsequent management of them. 

 While some conceive that every kind of water 

 should have equal effect upon equal soils, or that 

 its etficacy should .yield equal returns from the 

 poorest as from the richest soils, others esteem it 

 sufficient merely to bring water upon the land 

 without regard to its continuing to run or to stag- 

 nate upon it; and others overstretch their water, 

 spreading it over such a large portion of land as it 

 cannot cover in a body sufficiently deep to afford 

 the plant an adequate winter shelter; and lastly, 

 others conceive that, if the meadow has been, once 

 regularly formed, no farther care of it is necessary, 

 although it is obvious that, by the continued action 

 of the water, alterations may be made upon the feed- 

 ers and dischargers which may render them, if not 

 corrected, unfit fur the purposes they were designed 

 to accomplish. 



In the following pages I shall chiefly state the 

 object held in view in the irrigating system, as 

 practised in Gloucestershire and Wiltshire, where 

 t^e system has the longest prevailed and with the 

 best success, and in other places where it has been 

 introduced more lately, together with the means 

 by which these objects are endeavored to be ef- 

 fected. 



Formation of loater meadows. 



Before I begin to point out the particular mode 

 of ibrming an irrigated meadow, some questions 

 will be necessary to be proposed; such as, will the 

 stream of water to be used in irrigating admit of a 

 dam across it / can you dam up the water high 

 enough to run over the surface of your land with- 

 out injuring your neighbor's land? or is the water 

 already high enough without a dam? or can you 

 make it so by diverting it out of the stream higher 

 up, and, by a conductor, carry it nearly level till it 

 enter the meadow? and can you draw it off your 

 meadow as fast as it is brought on, without being 

 stagnated on the surface? This should be partic- 

 ularly attended to in the formation of every irri- 

 gated meadow, for experience shows that wher- 

 ever water is allowed to lie on the surface for any 

 considerable time, the finer grasses disappear, and 

 the whole surface, in a very short time, will be 

 completely covered with nothing but stinted aqua- 

 tic plants. Another precaution in the formation 

 of an irrigated meadow is of the greatest conse- 

 quence, I mean draining; lor unless a piece of 

 land that is to be converted into water meadows 

 be properly drained, although the surface be ever 

 so nicely formed, at the greatest expense, and the 

 richest water applied, the crops of grass or hay 

 will be very inferior to what they might have 

 been had the ground been properly drained; 

 therefore every irrigator, before he proceeds to 

 the execution of any of the works, should first 

 determine whether the drains that are necessary 

 to carry away the water from the meadow will be. 

 sufficient to free the soil from all subterraneous 

 water, otherwise arrangements must he made to 



that effect. Where you are free from all objec- 

 tions of this nature, your first operation is to take 

 an accurate level of the ground intended for irri- 

 gation, and compare the highest part of it with 

 the height of the surface of the water to be used. 

 Having found the surface of the water in the ri- 

 ver to be eight, twelve, or twenty inches higher 

 than the surface of the ground in the intended 

 meadow, which lies at the distance of one, two, 

 or three hundred yards, cut your main conductor 

 or main feeder, from which all the inferior feeders 

 branching from it are to be supplied, as straight 

 as circumstances will allow, directing it along the 

 highest side of the field rntended to be watered, 

 so that the separate ridges into which the mea- 

 dow is to be divided may have an equal slope 

 from it to the discharging drain, keeping up its 

 luniks, not on a dead levei, but with a gradual de- 

 scent from one end to the other, giving ihe whole 

 length an equal degree of fall, and then every 

 drop of water will be kept in equal and constant 

 motion. 



Sometimes the surface of the land has two or 

 three considerable swells higher than the rest; it 

 will then be necessary to give each side or part its 

 respective conductor, with feeders branching from 

 them, which will be found, whatever be the form 

 or situation of the meadow, to be competent to ef- 

 fect a true distribution of the water over the whole 

 surface of the land. 



The breadth of each main conductor depends 

 upon the quantity of water it is to convey, the de- 

 scent from the bottom of the stream to the surface 

 of the ground intended for meadow, together with 

 the number and length of the feeders which it is 

 to supply with water. The depth of the conduc- 

 tors, at their junction with the stream orriversup- 

 plying the water for irrigation, should be regu- 

 lated by the depth of' the stream or river, and the 

 lowest part of the land; i. e. it should, if the sur- 

 face of the land will possibly admit, always be 

 made as deep as the bottom of the river, by which 

 means the water will carry a larger quantity of 

 mud with it from the bottom of the stream. 



The stuff taken out in forming the conductors 

 is used in Ibrming the banks; or where not wanted 

 for that purpose, in levelling any inequalities on 

 the surface of the meadow. 



To give the meadow a proper command of the 

 water, it is requisite to place a sluice in the mouth 

 of each main conductor, in order to admit or ex- 

 clude the water at pleasure; and in droughty sea- 

 sons, when there is not water enough for the 

 whole at one time, the manager will thus be en- 

 abled to confine the water to any one part at plea- 

 sure; likewise, by paying attention in building in 

 the sluices according to the height of the different 

 swells of the ground, a considerable sum of mo- 

 ney might be saved in many situations; for, in- 

 stead of forming all the beds or ridges into one 

 common level, they can be formed according to 

 the different swells. All sluices should be built in 

 with hewn stone and lime; wherever this has been 

 neglected, I have always found the expense of 

 continual reparation to have been much greater in 

 a few years than what it would have been if the 

 work had been substantially done at the first for- 

 mation. 



The next part of the process is to make the 

 mam drain, which is to receive and carry off the 

 water after having irrigated the ridges into which 



