of the Liquid Manure of a Farm. 
(liate efficacy, which arc due to the soluble state in which it. 
holds the elements which form the structure of plants. Fibrous 
matter, or particles, visible to the eye, and which may yet be 
held in suspension, must be decomposed before they can be 
absorbed by plants, as the most powerful microscope fails to 
detect the apertures to their sponf^fioles. The conclusions of all 
horticulturists are in favour of fre([uent applications of manure in 
solution and very lar<i^ely diluted ; and on this practice depends 
the profit to be gained, by a speedy conversion of manure into 
food, and food into manure and money, so that the process may 
be repeated four or five times in the season, illustrating the com- 
mercial princij)le of quick returns. The cast-iron main leadings 
from the pumps must be laid 20 inches underground, and termi- 
nate in the centre of the ground to be irrigated ; the suction and 
main pipe to be 4 inches inside diameter, and, as a rule, the 
longer the suction-pipe the larger must be the diameter. This 
will be all the fixed piping I propose to have. I may remark 
that, in laying down pipes, every care should be taken to avoid 
right-angle turns or sharp bends ; the disregard of this rule will 
involve a great loss of power. The bad effect of angles on pipes 
is clearly manifested in the experiments of Rennie, published in 
the Philosophical Transactions of the Royal Society. From a 
pipe 15 feet long, 1^ inch diameter, under a head of 4 feet, he 
had delivered during equal intervals of time — 
Cubic feet. 
From the straight pipe 4196 
From tlie pipe with fifteen semicircular bends .. 3094 
„ „ one right angle 3334 
„ ,, with twenty-four riglit angles 1519 
Another point worthy of attention is well stated in an able 
French ti'eatise on hydraulics. " The pipes of which conduits 
are formed are generally more or less deformed ; their section is 
not always circular, and the interior surface is often coveretl with 
superfluous ridges and asperities which retard the motion. 
Where there are joints, the direction of the axis of the whole 
conduit is not always an unbroken line; the interior surface is 
not cylindrical ; the edges of some of the pipes advance inwards,, 
and form projections ; the fluid lines which arrive at the projecting- 
parts are arrested, divided, and sometimes thrown back ; hence 
disturbances in the motion, loss of motive force, and a sensible 
reduction in the discharge." 
At that part of the main-pipe which coming from the home- 
stall enters the square at A (if our area of 20 acres be represented 
by the sketch below), a branch with two arms will have to be 
brought to the surface of the land, and the same at the termina- 
tion of the main-pipe at B. As only one of the two arms on each. 
