it used to be sold, not rented, at from 5s. to 7s. (15 to 20 francs per hectare). But now it is capable, thanks to the work of the Flemish peasants and to irrigation, to produce the food of one milch cow per acre — the dung of the cattle being utilised for further improvements.
The irrigated meadows round Milan are another well-known example. Nearly 22,000 acres are irrigated there with water derived from the sewers of the city, and they yield crops of from eight to ten tons of hay as a rule; occasionally some separate meadows will yield the fabulous amount — fabulous to-day, but no longer fabulous tomorrow — of eighteen tons of hay per acre, that is, the food of nearly four cows to the acre, and nine times the yield of good meadows in this country.82 However, English readers need not go so far as Milan for ascertaining the results of irrigation by sewer water. They have several such examples in this country, in the experiments of Sir John Lawes, and especially at Craigentinny, near Edinburgh, where, to use Ronna’s words, “the growth of rye grass is so activated that it attains its full development in one year instead of in three to four years. Sown in August, it gives a first crop in autumn, and then, beginning with next spring, a crop of four tons to the acre is taken every month; which represents in the fourteen months more than fifty-six tons (of green fodder) to the acre.”83 At Lodge Farm they grow forty to fifty-two tons of green crops per acre, after the cereals, without new manuring. At Aldershot they obtain excellent potato crops; and at Romford (Breton’s Farm) Colonel Hope obtained, in 1871–1872, quite extravagant crops of various roots and potatoes.84
It can thus be said that while at the present time we give two and three acres for keeping one head of horned cattle, and only in a few places one head of cattle is kept on each acre given to green crops, meadows and pasture, man has already in irrigation (which very soon repays when it is properly