58 
On Water Supplies suited to 
gallons per annum, hence the large deficiency of, at least;, 
76,000 gallons would have to be made up. The only way to- 
do this, in localities where the rainfall alone must be looked 
to, is to form artificial gathering grounds by railing in a suffi- 
cient area of land (if sloping, so much the better), and after 
forming the surface so as to drain to a particular point, to cover 
it with a layer 3 inches thick of cement, concrete, or bricks^ 
on flat laid in cement, or stone shingles set in the same way. 
To collect 76,000 gallons at 12"4 gallons per square foot per 
annum, would need a gathering ground of 1^^^^^ = 6130^ 
square feet, or 681 square yards, or a little over 26 yards square. 
The cost of this, including a fence round the ground, would be 
about 80/. A storage reservoir of '^^"^^ = 30,166 gallons- 
would have to be provided to take the water of the roofs and 
gathering ground at a cost of about 150Z., so that for an outlay 
of about 230/. my house could be made independent of the 
water company. 
My water rate comes to 11/. lis. per annum, which is about 
5 per cent, on the above outlay, so that the rain water would cost 
no more than the pipe water ; I should, however, have to pump 
a portion of it to the top of the house, which would involve some 
expense. 
The water collected in this way would be cleaner than that 
taken from the roofs only, and filtration, except for table pur- 
poses, might be dispensed with, as the settlement in the large 
storage reservoir would make the water fairly clear. 
It is sometimes possible to make such artificial gatherings 
grounds at some distance from the house on ground sufficiently 
high to command it completely ; in such cases an admirable 
water supply may be assured, and by making the area of the 
ground sufficiently large, and the storage-tank of adequate 
capacity, an abundant provision may be made against fire, and 
even for providing power for working lifts and hydraulic motors 
for domestic or for dairv purposes, especially as the waste neater, 
after having been used in these appliances, can be employed 
for many purposes in the houses and gardens. 
The larger the annual rainfall, the cheaper it is to carry out 
the arrangements necessary to collect and store it. 
Artificial gathering grounds may be laid out at about Is. lOJ. 
per square yard, with about 35. per lineal yard for fencing all 
round, and underground reservoirs cost about 6/. 10s. per 1000 
gallons, when the capacity is below 20,000 gallons, and from 
4/. 10s. to 5/. per 1000 gallons for larger reservoirs. 
Before proceeding to consider the nest sources of supply^ 
