Sewarje-Farmintj. 
413 
larg^er area of land than lias hitherto been deemed practicable 
— if a considerable amount of the produce finds its own market 
in the mouths of cattle upon the farm, and if dung can be 
made available for such crops as especially need it — these, I 
take it, are substantial advantages, and such as are likely to 
advance this mode of sewage utilization. It will not do to put 
the 15/. an acre, which the corn-crop may be expected to pay, 
in gross, against the far larger returns from occasional specu- 
lations in market-garden or other produce, unless at the same 
time the farmer reckons the benefits to those other crops and the 
other advantages which are likely to accrue from the adoption of 
this method. 
I must not be understood as advocating, under all circumstances, 
the growth of corn. In cases where straw is cheap, or where 
stable manure is procurable at a low price, it may be advisable 
to concentrate the liquid manure upon a smaller acreage ; in such 
cases nearly all the advantages I have described might be 
reaped without the drawbacks. 
Modes of Ceopping. 
Taking the hypothetical case of a farm of 500 acres receiving 
the sewage of a population of 20,000 persons, or at the rate of 
40 persons per acre, I will now endeavour to estimate what return 
may reasonably be looked for, were such a system as I have been 
describing carried out. The amount of water-supply before men- 
tioned, viz. 50 tons per head per annum, would afford a total of 
1,000,000 tons annually for the irrigation of this farm ; or, in 
other words, 2000 tons per acre would be at the disposal of the 
farmer over the entire area of his land. But if 150 or 200 acres 
of this could be cropped with corn, a much larger supply would 
be available for the remainder, since moderate application would 
only be required for the cereals grown in succession, whilst those 
after cabbage, mangold, and similar produce, should require no 
irrigation at all. On the following page I have endeavoured to 
show that, at the present market value of sewage, a reasonable 
remuneration might be expected from the adoption of this course. 
1 shall assume that, in the case in point, 200 acres are annually 
cropped with cereals, 100 acres with rye-grass, 50 with mangold, 
50 with cabbage, and that 100 acres are devoted to market-garden 
crops. The following table and diagram will plainly show the 
course of cropping upon the 400 acres of farm land. I will 
suppose the land divided into plots of 50 acres, each of which is 
represented by a column in the diagram : — 
