176 On Irrigation in Tasmania. 
island. It must be remembered that these estimates 
are all for land to be watered throughout the summer, 
or for half the year: only one-third of this quantity 
of water would be required for grain land. 
Advantages .—There seems scarcely any room for doubt 
that, at the highest rate above estimated, the profit arising 
from irrigation in the present state of the colony would 
be greater than that arising from any other employment 
of capital. The produce of irrigated land is not a 
matter of doubt; sufficient has been already done by en¬ 
terprising individuals to show what it is ; and, indeed, so 
well are these effects known, that the main point now 
is rather to show the practicability of carrying out the 
system extensively, aud the means and probable expense 
of doing it. 
The effect of the system, if extensively carried out, 
must be incalculable. There are several hundred thou¬ 
sand acres in the colony capable of being irrigated by 
some one of the methods suggested; and the gross pro¬ 
duce *of an acre of land irrigated throughout the summer 
will on an average be probably threefold that of land not 
supplied with water. Besides the plan of laying down 
with grass such land as is fully irrigated, no doubt a 
system of cultivation will be discovered by which the land 
may be first employed to produce a white crop, and be¬ 
tween the harvest and seed-time some intermediate crop, 
which the water will enable it to bear. At present, 
indeed, it seems evident that nothing could be more pro¬ 
fitable than grass; but it would be well that the attention 
of the agriculturist should be given to the question of 
the best system of cultivation for such irrigated lands, in 
the case of that happening which may confidently be 
expected, that the demand upon the colony for grain and 
potatoes will far exceed any thing that has yet been 
witnessed. Now that the subject of emigration lias been 
