IRRIGATION. 



From the Farmer's Encyclopedia. 

 In agriculture, the waieriiiff of the earth, to 

 increase its produciiveness. The term, however, 

 is confined to that species of flooding which con- 

 sists of spreading a sheet ol" water over a field or 

 meadow, in such a manner that it can be easily 

 withdrawn. 



Irrigation, or the artificial wateringof the earth, 

 chiefly to produce increased crops of grass, lias 

 been in use from a very early period. In Oriental 

 countries, in (act, the heat, of the climate is such, 

 that, in many situations, the now productive soil 

 would be absolutely sterile, were it not that the 

 cultivator enriches his ground with a copious sup- 

 ply of water. The simile employed by Isaiah, 

 (i. 30.), to indicate barenness and desolation, is 

 " a garden that hath no water.". And that, in pa- 

 triarchal times, they labored hard to supply their 

 grounds with water, by means of various hydrau- 

 lic machines, some of which resembled the water- 

 wheels of the fen districts of England, and were 

 worked by the feet of men, something after the 

 style of the modern tread-mill, is certain. Moses 

 alluded to this practice when he reminded the 

 Israelities of their sowing their corn in Egypt, and 

 watering it with their feet (Deut. xi. 10 ; 2 Kings 

 xix. 24,) and in the sandy soils of Arabia the 

 eame system is still continued (Niebuhr, vol. i. 

 p. 121). According to Dr. Shaw, the following is 

 the modern mode of" raising and using the water 

 of the Nile for the purpose of irrigation in Egypt : 

 " Such vegetable productions as require more 

 moisture than what is occasioned by the annual 

 inundation of the Nile, are refreshed by water 

 that is drawn at certain times out of the river, 

 and lodged in large cisterns made for that pur- 

 pose. The screw of Archimedes seems to have 

 been the instrument formerly made use of for that 

 purpose, through at present the inhabitants either 

 supply themselves with various kinds of leathern 

 buckets or else with a sakiah, as they call the Per- 

 sian wheel, which is the most useful and generally 

 employed machine. Engines and contrivances of 

 both these kinds are placed ail along the banks ol 

 the Nile, from the sea to the cataracts, their situ- 

 ations being higher, and consequently the ddTiculty 

 of raising the water being greater, as we advance 

 up the river. When their pulse, saffron, melons, 

 sugar-cane, &c. (all of which are commonly 

 planted in rills,) require to be refreshed, they take 

 out a plug from the bottom of the cistern, and 

 then the water gushing out is conducted from 

 one rill to another by the gardener, who is always 

 ready, as occasions requires, to stop and divert the 

 current." In Egypt at the present day, according to 

 Dr. Clarke, the water is sometimes raised, (or the 

 purposes of irrigation, by means of a wicker 

 bastfet, lined with leather, which is held by cords 

 between two men, who, by this laborious means, 

 swing it over the banks of tho Nile into ifie canal 

 which conveys it to the lands intended to be irri- 

 gated. A machine similar lo the Persian wheel is 

 still employed in China by the cultivatorsj fijr the 

 VoL= X.-25 



purposes of irrigation. Tliis use of machinery 

 for the purposes of watering might in fact, in 

 many situations, be advantageously employed in 

 England, to a much greater extent than is com- 

 monly believed. It is well known how many 

 thousand acres of valuable land are profitably 

 drained by means of the steam-engine. At this 

 very period a public company is proposing lo en- 

 close and drain an arm of the sea in Lincolnshire, 

 by the assistance of its gigantic aid. Yet how 

 rarely, if ever, is that power employed lo irrigate 

 the thirsty lands of England ; lands of all others 

 the most profitable, the best adapted for the forma- 

 tion of water meadows ? The tracts to which I 

 allude are those on a slope, as on a side of a hill ; 

 but these are rarely found in situations where a 

 sufficiently copious supply of water can be con- 

 stantly obtained for the purposes of irrigation. 

 Yet the quantity thus required is not so large as 

 to be beyond the power of the steam-engine to 

 supply ; thus, to eufficienily saturate a square 

 yard ol a calcareous sand soil with water to the 

 depth of one foot, as in irrigation, requires about 

 30 gallons of water, equal to about 145,000 

 gallons per imperial acre. Now, that the steam- 

 engine could readily and profitably supply this 

 quantity of water, may be concluded from several 

 lacls ; thus, the two engines, one of eighty, the 

 other of sixty horses' power, which keep Deeping 

 Fen, near Spalding, completely drained, when 

 working, in 1835, only ninety-six days, of twelve 

 hours each, raised more than 14,000,000 tons of 

 water several feet. The district drained by them 

 contains about 25 000 acres (Brit. Farm. Mag. 

 N. S. vol. iii. p. 800), which would otherwise he a 

 complete swamp. And it has been proved that by 

 a common condensing steam-engine, one bushel of 

 coals would raise more than 50,000,000 lbs. of 

 water one foot. In many situations, therefore, 

 where, for the purposes of irrigation, good river 

 water can be copiously obtained, and fuel is at 

 a moderate price, I ain confident that great results 

 are yet to be obtained by the aid of mechanical 

 power. For, by the steam-engine, the soils of all 

 others the beet adapted for irrigation may be suc- 

 cessfully brought into cultivation ; for instance, 

 the poor sands and gravels on the sloping banks 

 of many of the English and Scottish rivers, many 

 of whose waters, fi-om being charged with or- 

 ganic matter, the carbonate and sulphate of lime, 

 and various earthy substances, are excellent for 

 the use of water meadows. The early employ- 

 ment of irrigation by the Egyptians and Chinese 

 was most likely 'the result of the good efTecia 

 which were observed to be produced by the over- 

 flowings of the Nile and the Chinese rivers ; for 

 in the " Celestial Empire," irrigation has, it seems, 

 been employed, according to their veracious his- 

 torians, lor a period long before that assigned to 

 the flood. Ill Italy, especially on the banks of the 

 Po, the cultivators of the earth have certainly 

 employed this process for a period previous to the 

 days of Virgil. ( Georg. lib. i. v. 106-9) — 



Deinde satis fluvium inducit, rivosque sequeutes — 



