724 niACTICE OF AGRICULTURE Part III. 



powerful than on other descriptions of land. There are also some strong adhesive sour 

 wet lands, such as are common in the vicinity of large rivers, which are also capable of 

 being improved by watering ; but the beneficial effects are not in such cases so soon pro- 

 duced as on the first sorts, nor is the process so advantageous to the farmer, on account 

 of the very great expense to which he must, in many cases, be put by previous draining. 

 There are some other lands, as those which contain coarse vegetable productions, as 

 heath, ling, rushes, &c. which may likewise be much improved by watering. It must 

 be kept constantly in mind, in attempting this sort of improvement, that, the more tena- 

 cious the soil is, the greater should be the command of water for effecting the purpose ; 

 as a stream, capable of watering fifteen or twenty acres of light dry land, would be found 

 to be beneficial in but a small degree when applied to watering half the same quantity of 

 cold clayey ground such as in its natural state abounds with coarse plants. On all soils 

 of the latter kind a considerable body of water for the purpose of floating them is required 

 to produce much beiiefit, and where a suflScient quantity cannot be procured, this mode of 

 improvement will seldom answer the farmer's intention or be advantageous in the result. 



4387. Smith, an experienced irrigator, supposes that " there are only a few soils to which irrigation may 

 not be advantageously applied : his experience, he says, has determined, that the wettest land may be 

 greatly improved by it, and also that it is equally beneficial to that which is dry." {Obs. on Irrigation, 



&c.) But, as many persons unacquainted with the nature of irrigation maybe more inclined to the latter 



the; " .... 



: - \ 'ry. 



care must be taken to render them perfectly dry when the business of floating shall terminate ; and that 



supposition than the former, he explains the reason of wet land being as capable of improvement from 

 flooding as that which is completely dry. It is, that, in the construction of all water meadows, particular 



the season for floating is in the winter and not in the summer, which those who are unacquainted with 

 the process have too generally supposed. All peat bogs are certainly of vegetable origin, and those vege- 

 tables are all aquatic. It follows that the same water which has produced the vegetables of the bog would, 

 under due management upon the surface, produce such grasses, or other vegetables, as are usually grown 

 by the farmer ; and he has hitherto had reason to think that this may be considered as a general rule for 

 determining the situation of any experiments with water. The lands that permit of this sort of improve- 

 ment with the most success are such as lie in low situations on the borders of brooks, streams, or rivers, or 

 in sloping directions on the sides of hills. 



4388. TIw purity of the water to he used in irrigation is supposed by some to be 

 a matter of the first importance ; but it is now fully proved, by the accurate experi- 

 ments of an able chemist, and by the extraordinary growth of grasses in Pristley meadow, 

 in Bedfordshire, that ferruginous waters are friendly to vegetation, when properly applied. 

 (Smith's Observations on Irrigation, p. 28.) Lead or copper never does good, and it is well 

 known, that waters of that description, after they have been brought into fields, by levels 

 cut at a considerable expense, have again been diverted, and suffered to flow in their original 

 channels. Waters impregnated with the juices that flow from peat-mosses, are consi- 

 sidered by many not worth applying to the soil. It is objected to them, that they are 

 soon frozen, that they convey no material nutriment, and that they are commonly loaded 

 with such antiseptic substances as, instead of promoting, will retard vegetation. (Dr. 

 Singer's Treatise, p. 579.) It is urged, on the other hand, that a want of suflScient slope 

 in the meadow, or of proper management in regard to the water, may have occasioned 

 the disappointments experienced in some cases, when bog-waters have been applied. 

 (Derbyshire Report, vol. ii. p. 463.) 



4389. The advantages of watering lands must, in a material degree, depend on the 

 climate. It is evident that the benefit to be derived from this process in Sweden, for 

 example, where the summers are short, must be greatly inferior to what it is in Lom- 

 bardy, where grass grows all the year ; and that in Perthshire, where grass ceases to grow 

 for at least three and often four months in the year, it must be much less than in Glouces- 

 tershire or Ireland, where its growth is not interrupted above a month or six weeks, and 

 sometimes not at all : most grasses vegetating in a temperature of 33 or 34 degrees. 

 Still, however, as the most luxuriant pastures are found on lands naturally watered, both 

 in Sweden and Perthshire, it would appear worth while to imitate nature in cold as well as 

 in warm countries. According to many vnriters on the subject, the benefits attending 

 watering in England are immense. In Davis's Survey of Wiltshire, it is calculated that 

 2000 acres of water meadow will, on a moderate estimate, produce, in four or five years, 

 10,000 tons of manure, and will keep in permanent fertility 400 acres per annum of 

 arable land. 



4390. Watering poor land, especially if of a gravelly nature, is stated in The Code of Agriculture to be 

 by far the easiest, cheapest, and most certain mode of improving it. " Land, when once improved by 

 irrigation, is put in a state of perpetual fertility, without any occasion for manure, or trouble of weedmg, 

 or any other material expense. It becomes so productive, as to yitld the largest bulk of hay, besides 

 abundance of the very best support for ewes and lambs in the spring, and for cows and other cattle in the 

 autumn of everv year. In favourable situations, it produces very early grass in the spring, when it is 

 doubly valuable'; and not only is the land thus rendered fertile, without having any occasion for manure, 

 but it produces food for animals, which is converted into manure, to be used on other lands, thus augment- 

 ing, in a compound proportion, that great source of fertility." Were these advantages more generally 

 known, or more fully appreciated, a large proportion of the kingdom might become like South Ccrney, m 

 Gloucestershire, where every spring, or rivulet, however insignificant, is made subservient to the purpose 

 of irrigation, fertilising, in proportion to its size, either a small quantity or a large tract of land. {Glouces. 

 tershire Report, p. 280.) 



4391. Irrigation by liquid manure may occasionally be practised in the neighbourhood 

 of towns and cities to the greatest advantage. In the neighbourhood of Edinburgh, we 



