UTILIZATION OF SEWAGE. 
675 
water introduced came in, not from the top, but from under 
the bottom of the filtering-bed, and so, by their own force, 
rising to their own level, the watery parts forced their w r ay 
through the filtering-bed, leaving the solid materials at the 
bottom. The filtering-bed consisted of three separate wooden 
trays, each covered with three or four inches deep of burnt 
bog-soil. They were separate from each other; the water 
gradually forced its way from the lowest to the upper one ; it 
then fell over the vacant space, and dropped again to the 
bottom of the second filtering-bed, through which it rose 
again in the same way, obtaining a similar amount of filtration. 
Now, I have very shortly made clear what is the process, and 
what is the principle. Each of these separate trays was 
capable, as they absorbed the manure, of being withdrawn 
and renewed, and fresh trays substituted for them, to collect 
a fresh amount of sewage. Now, as to the expense of this 
operation: I wish briefly to mention to you what has been 
the expense, so far as my observation has gone, and what has 
been the result. In the first place, the original expense of 
land, tank, and pipes leading from the tank, was £113. In 
the course of the nine months during which the college is 
open, w T e have collected from the bog-soil W'hich was placed 
upon the premises an amount equal to ninety-six tons of the 
best manure, equal, at a value of 8«s. a ton, to £38 a year, or 
one third of the whole expense, in the first year of the tank 
which we established. But the solid manure so obtained was 
not our object; that was an object obtained by the way; but 
our object was to obtain the liquid manure for the purpose of 
irrigation. To give you an idea of the sort at Wellington 
College, let me tell you, that when we first purchased the 
land we gave £10 an acre for the fee simple of it, and we were 
told that we had given twice as much as it was worth. In 
pointof fact, it is the very worst description of Bagshot Heath— 
a thin layer of worthless sand above a mass of gravel, which 
is utterly impenetrable to water; a disagreeable soil, varied by 
an occasional swamp, with some bog-soil in it. The lower 
land certainly is of a deep brown clay, which, when reclaimed, 
is the more valuable portion. Now, this land had never pro¬ 
duced a blade of grass before we took it in hand; and from 
this small tank we made the experiment last year. I admit 
it was on a small scale; and we have now thirty or forty poles 
under grass, and from this we obtained in one year eight cut¬ 
tings of the finest grass, beginning on the 7th of April to cut 
our first crop, cutting it every three weeks for the next half- 
year, and yet half of the crop which was left was at least one 
foot in height. In addition to this, we supplied by our 
own means from this soil, the college with potatoes and 
