S16 



IRRIGATION. 



Reference 



land. 



that it may be ascertained with a considerable degree 

 of assurance before expensive efforts are made. 



The qualities of the water, and the natural produce 

 which it nourishes most effectually, being discovered in 

 the first place, it belongs to the farmer to consider the 

 population and markets of the district, his own de- 

 mands, and the nature and extent of the irrigated crops 

 by which he may expect to derive most profit. A pru- 

 dent man will be determined in a considerable degree 

 by these consdcrations, before he embark deeply in the 

 undertaking. 



The water meadows of England present a fine view 

 to statistical o f irrigation for grass, a description of which belongs 

 descriptions rather to other portions of this work, and will partly 

 be found under the article AGRICULTURE, and in those 

 works to which reference is there made. A similar ac- 

 count of French irrigation -will be found under the ar- 

 ticle FRANCE of the present work ;' and that of Lom- 

 bardy and other nations, will fall to be introduced un- 

 der other heads. 



State of this In Scotland there have been many successful essays 

 art in Scot- in irrigation on a lesser scale ; but the greatest attempt 

 was made by the late Duke of Buccleuch on his pasto- 

 ral estate on the rivers Esk, Ewees, Tiviot, Etterick, 

 and Yarrow. Neither the water nor the climate in ge- 

 neral, were favourable to this liberal effort on the great 

 scale on which it was made ; and the wants and popu- 

 lation of the district hardly warranted that scale ; be- 

 sides, it was conducted mostly in that mode which re- 

 quires most water and most expence ; and it was ne- 

 cessary for this purpose to sacrifice too much of those 

 level soils which are most valuable for other purposes 

 in that alpine part of Scotland. The art of irrigation is 

 best promoted when success as well as failure are pro- 

 perly recorded ; and the failure of this great attempt is 

 particularly accounted for in the Farmer's Magazine, 

 1815, page 42, &c. But many good specimens of irri- 

 gation occurred under this attempt, some of which are 

 still preserved ; and many other successful efforts have 

 been made by watering for improving the meadows in 

 all quarters throughout Scotland, the climate and richer 

 waters of England being, however, generally prefer, 

 able. 



There, in favourable circumstances, it is common to 

 obtain by irrigation three successive crops, viz. two of 

 pasture grass, and one of grass cut for hay or soiling, all 

 in one year. This fact leads us to consider the climate 

 in connection with soil, and water, and other circum- 

 stances ; and in applying this art to the agriculture of 

 many foreign parts, a similar advantage is obtained by 

 nourishing various crops in the same year. 



Prospect of The resources which may yet be opened to many na- 

 gencral fu- tions by means of irrigation, fully understood and prac- 

 ^ s advan ~ tised, appear to exceed all present calculations ; and 

 what is already known of this art is amply sufficient to 

 attract towards it the notice of the legislator as well as 

 that of the husbandman. Water may be made to fur- 

 nish a rich and extensive supply of manure to the soil, 

 merely by giving it a proper direction, which will have 

 the further good effects of preventing that waste and 

 ruin which frequently accompany this element when 

 t is left without any direction. Even the drainage of 

 wet soils may thus be rendered valuable for the im- 

 provement of other lands, and what naturally tends to 

 do harm may be turned to advantage. 



It has become, in most of the cultivated parts of the 

 expensive, globe, a serious and expensive matter to preserve the 

 soils in full bearing by regular and frequent manuring. 

 1 he cost of hrae, dung, and other fertilising substances, 

 is considerable, and the carriage and application add 



Result and 

 success in 

 England. 



uges. 



Manuring 



materially to it ; nor is it always in the farmer's power Irrigati^ 

 to apply his manures in the proper season, % and to the ^-"V" 

 requisite extent. ^ 



Irrigation supplies manure in favourable circum- Irrigation 

 stances, at less expence, and with more effect, than al- facilitates 

 most any other mode, on the soils to which it is applied ; ^j*""," 1 " 

 and the produce of it on these furnishes increasing gjj^j j,*. 

 means for the manure of other soils. The limits of this provement 

 beneficial operation appear as unfixed as its advantages of a coun- 

 are liberal ; and as the population increases, these li- "? 

 mits extend by the simultaneous enlargement of the 

 means and the returns. It naturally connects itself 

 with draining and embankment, and is therefore capa- 

 ble of great extension, as the radical improvements of 

 a country advance. In short, whatever occasional er- 

 rors may be committed in irrigation, it is an art that 

 will naturally and ought to advance, in any well go- 

 verned country, along with the population and general 

 improvement. 



The proper modes of conducting the operations of Flat me- 

 this art must be varied greatly in respect of particular tl|0(1 of w - 

 circumstances. A flat soil requires to be floated in te ""3- 

 ridges by means of a full supply of water, the feeders 

 on the crowns, and the drains in the furrows ; but this 

 method is expensive in the forming as well as in the 

 supply of water ; it requires land suitable for the plough, ' 

 and therefore valuable otherwise ; and it succeeds ful- 

 ly only when the waters are rich and the climate good. 

 All these circumstances, however, frequently concur in 

 England to recommend it. 



Catch- work is applied on dry barren slopes, where Catch-work 

 the operator sends the water in succession over differ- mwtaA 

 ent parts of the surface, accommodating his operations 

 to the natural form of that surface. This method is at- 

 tended with little expence, and may answer well in al- 

 most every case where water is not plentiful, and cir- 

 cumstances unfavourable to flat forming. 



It is an error to think that very long continued wa- Proper can- 

 tering is productive in proportion. On the contrary, t inuance f 

 irrigation must not be continued for too long a time at ^ ' t c " e 

 once on any grounds, otherwise the finer grasses and t j mei 

 plants are thereby destroyed, and a set of coarse aqua- 

 tics brought up in their place. Repeated waterings are 

 necessary indeed ; but the general practice does not 

 seem to recommend above three weeks at one time in 

 cold weather, half of that time in moderate weather, 

 and one week when the season is warm ; on the whole, 

 about six weeks in the year. 



In the particular works and operations of irrigation, Reference 

 the precautions necessary when sheep are to be fed '* J 

 on watered lands, the plants most suitable, and the wc 

 value and application of the produce, we refer to those 

 works already quoted, and others in which the peculiar 

 practice of irrigating for grass in Britain is detailed ; 

 including among these last the treatises written by Mr. 

 Wright, Mr. Boswell, and Arthur Young, and the 

 Highland Society Transactions. (K. k.) 



IRRITABILITY. See BOTANY and PHYSIOLOGY. 



IRVINE, or IHWINE, is a sea-port town and royal 

 burgh on the west coast of Scotland, in the county of 

 Ayr. It is situated on a rising ground on the north 

 side of the mouth of the river Irvine, which runs into 

 the Firth of Clyde, and consists of a broad street, run- 

 ning from south-east to north-west, of a suburb on the 

 south side of the river, inhabited by seafaring people, 

 and connected with the town by a good bridge, and of 

 another suburb on the road leading to Ayr. The prin- 

 cipal public buildings in Irvine are the church, which 

 has an elegant spire, and stands on a rising ground 

 between the town and the river, and the town- hall, 



