Italian Irrigation. 
195 
culjic foot, which is applied to an area of 83 acres at a cost of 
about 3f/. per acre. 
The broad distinction thus lies between districts charged 
11. to 13^. per cubic foot per second and 3s. or 4s. per acre, and 
those which pay up to 40/. and contrive to supply about 80 acres 
at the rate of 10s. per acre. 
As to the quantity of water to be given to meadow-land, 
Colonel Baird Smith tells us that there is a great variety of 
opinion. " According to an experiment of De Regi," he writes, 
"the continued discharge of 1 cubic foot per second is sufficient 
for the irrigation in 24 hours of 4 acres. Hence, as the total 
volume discharged in that time amounts to 86,400 cubic feet, 
and the area watered to 174,240 square feet, it appears that a 
stratum of water equal to nearly 6 inches in depth Avas in this 
case spread over the surface bi the meadow." As the general 
period of rotation may be taken at 14 days, the cubic foot would 
suffice for (12+4) 48 acres, there being 12 periods of 14 days 
in the summer season. "The above estimate, however, implies 
that the whole water is absorbed by the soil, which, in point of 
fact, is never the case. Lombard engineers calculate the absorp- 
tion in each watering as ranging from one-half to one-third of 
the total quantity of water employed. 
Effectively, the irrigating power of any given quantity of water 
employed in meadow irrigation is twice the area watered on the 
first application. 
But the Lombard farmer by no means relies exclusively on 
the fertilising power of water, but manures freely — especially his 
winter meadows ; for these last pig-manure, applied in a liquid 
form, has the preference, and it is calculated that 3 pigs kept 
throughout the year suffice for 1 acre. Stock-manure is com- 
bined with the earth taken out of the carriers, &c., and applied 
at the rate of 12 tons per acre, or linseed oilcake (!), mixed with 
one-seventh of its weight of lime, is given at the rate of 15 cwt. 
as a dressing. The application of sewage is not as general as 
we may imagine ; a proper system of sewers having been or- 
ganised in a part only of ]Milan, the rest of Italy retaining the 
use of the night-cart. 
XV. — On the Measurement of Water. ^ 
The history of irrigation abounds with warnings as to the 
" danger of allowing a great system of irrigation to develop itself 
without well-defined regulations — of permitting interests to grow 
up either in ignorance or neglect, which, infringing the rights of 
government, oppose themselves afterwards with obstinacy and 
vigour to improvement of any kind." At the same time it is 
o 2 
