100 



THE FARMER'S MAGAZINE. 



fortnight's rain in the southern and midland dis- 

 tricts of England. Or, to regard it in another 

 point of view : supposing that 500 tons of sewage 

 per acre was required to thoroughly irrigate an 

 acre, then, by 1 cwt. of coals, an acre and a half of 

 land can be irrigated. 



These facts may be thus tabulated, the calcula- 

 tion being based upon the before-given datum of 

 1,600,000 gallons : 



One cwt. of coals \ 

 will raise J 



1 foot 1,600,000 gallons. 



2 feet 



4 „ 



8 „ 



12 „ 



16 „ 



800,000 „ 



400,000 „ 



200,000 „ 



133,333 „ 



100,000 „ 



But let us see how far more than this the great 

 Cornish engines accomplish, with the same ex- 

 penditure of fuel, these engines being especially 

 adapted to the pumping of water, and every ap- 

 pliance adopted to economise fuel. 



Now, from the average work of twenty-five of 

 these fine engines, reported a few years since, it 

 appears that by the consumption of 



One cwt. of coals 1 ,'c 4. r r.«,^ ^^^ n 



1 foot 6,200,000 gallons 



they raised 



'} 



3,100,000 „ 

 1,550,000 „ 



775,000 „ 



387,000 „ 



193,500 „ 



96,750 „ 



lies, that a Cornish 

 engine will raise about 96,750 gallons (or say 380 

 tons) to a height of 64 feet ; that an ordinary 

 engine can only lift 16 feet; and if we calculate 

 that so large a quantity as 9,000 tons of sewage are 

 needed for the most profitable irrigation of an acre 

 of land, and that this amount has to be raised 64 

 feet, why then the expenditure for coals would be, 

 in a Cornish engine, about 24 cwt. ; if the lift is 

 32 feet, then only about 12 cwt. would be required. 

 From an obhging communication, dated January 

 21, I860, from Messrs. Sandys, Vivian, and Co., 

 of Hayle, in Cornwall, I find that the average work, 

 or " duty" of the great Cornish engines is not 

 quite so much as that reported of the 25 engines. 

 These great engine makers observe, " we find the 

 average duty of our large Cornish pumping engines 

 is about 52,000,000 lbs. of water, (or 21,666 tons.) 

 lifted one foot high by 112 lbs. of Welsh coals." 



112 lbs. of coal would there- 

 fore raise ... 8 feet 

 Ditto , . . 16 „ 

 Ditto . . . 32 „ 

 Ditto . 1 . 64 „ 



2708 tons. 



1354 „ 

 677 „ 

 338 „ 



It is most probable that the quantity of sewage 

 which I have supposed requisite considerably 

 exceeds the amount that will under the best man- 

 agement be found sufficient. 



In irrigation with ordinary streams, the purer 

 the water the more copious is the amount that the 

 irrigator finds necessary. We learn from Mr. 

 Coombes, of Tisbury, that the quantity of the 

 bright chalk or oolite waters of Wiltshire, which 



the irrigated meads receive, is on an average about 

 2,000 gallons a minute. And yet we are all pretty 

 well aware that a much smaller quantity of a richer 

 liquid manure spi'ead over grass land is productive 

 of highly-beneficial results. Let us briefly refer 

 to what Mr. J. Bruce, of Ensham, reports {Jour. 

 Roy. Ag. Soc, vol. xiv. p. 432). By his mode he 

 finds fifty or sixty hogsheads of a mixture of pond- 

 water and liquid manure sufficient to flush an acre. 

 And then if we inquire the result of using on a 

 large scale a mixture of river and sewage waters, 

 where can we refer better than to the case of the 

 meads around the city of Milan in Northern Italy? 

 Of these celebrated meadows we have the advan- 

 tage of a report from the English Government 

 Commissioners — a digest of whose statement I have 

 elsewhere printed {Farmer's Almanac, vol. ix p. 31). 

 By these Commissioners (Messrs. Wa)% Austin, 

 and Southwood Smith) we are informed, these 

 valuable water meads surround the city on all 

 sides. The riv^r Vettabia, which carries away the 

 liquid refuse of Milan, is made to ii-rigate about 

 4,000 acres before it falls into the river Lambro, 

 about 10 miles from the city; the amount of water 

 flowing from the town equals 160 gallons per day 

 for each inhabitant ; the depth of water conveyed 

 on to the land, calculated over the whole area, is 

 about 8 feet yearly (9600 tons). This, it is calculated, 

 contains the liquid refuse of about forty persons. 

 A large portion of the water, however, is used over 

 again on fields of lower levels. No where, it seems, 

 is the water of the Milan river as muddy in ap- 

 pearance as that of the Thames at London Bridge, 

 and yet a large portion of the land irrigated with 

 it becomes so rich that the surface is pared oft" 

 every few years, to obtain the vegetable matter 

 (which gradually becomes too luxuriant) as manure 

 for other lands, for which it is highly prized. The 

 expense of forming a water meadow varies from 

 about £8 to £10 up to £40 an acre, according to 

 the nature of the original surface. The water 

 during the summer months is turned on to the 

 grass from six to ten hours about once a week ; 

 but a certain portion of these meads, called marcite, 

 are constantly irrigated by having a thin film of 

 the water passing over them. This flow is never 

 stopped except in ci'op-cutting time. These marcite 

 meadows require about 250,000 gallons of water 

 per acre; but then the water is afterwards em- 

 ployed on other meadows. The farm of Dr. 

 Chiappa, of about 580 acres, is about Sj miles 

 from the city. Here are about 80 acres of marcite; 

 the produce of these 80 acres supports 100 stall- 

 fed cows. Six crops of grass are cut during the 

 year, of the following proportion of weight. In — 



February, 800 kilogrammes per pertica. 

 April, 800 „ 5, 



June, 600 „ „ 



August, 600 J, „ 



October, 400 „ „ 



December, 400 „ ,, 



or about 22 tons of grass per acre per annum. 

 Hay is made in June and August. On hay the 

 cattle are fed about forty days in the year — at all 

 other times on fresh grass only. In judging of 

 the produce of these meadows, the effect of the 

 climate of Italy must be regarded, Let us then 



