Farms and Villages. 
37 
pipe should rise to about the middle of the sand layer, and 
should then pass out horizontally through the brickwork and 
terminate in a ball-cock in the clear-water tank. The object 
•of taking the pipe out about the middle of the depth of the 
sand is to prevent the water being drawn below that level, 
and so removing all risk of air getting into the lower part 
of the filter, and giving trouble when it fills again. The 
storage tank should have a capacity of about 120 cubic feet, so 
that the filter might run steadily night and day. The storage- 
tank would be best underground, for the reasons already given, 
and might be made in the form of a water-tight well 4 feet 
diameter and 10 feet deep. From this a pump worked by hand 
or by power would draw the water as required. The filter and 
the storage-tanks should be provided with covers to keep the 
water in the dark, to guard against accidental contamination, 
and to protect from frost. The underground tanks have an 
advantage over iron tanks in that they keep the water cooler 
in summer and from freezing in winter. Darkness is very 
advantageous, because it prevents the growth of weeds and many 
varieties of animalculae. 
Mr. G. M. AUender's estimate of the supply of water re- 
quired by a dairy-farm is much higher than the quantity which 
Dr. Parkes prescribes as a minimum ; he estimates that 10 gallons 
per head per day should be provided for horses and cattle, and 
5 gallons for pigs. The roof area of the Aylesbury Dairy Com- 
pany's farm at Horsham is 80,000 square feet, or nearly 2 acres. 
It covers, besides various offices, 168 cows, beasts and horses, and 
150 pigs, which require therefore a supply of at least 2430 
gallons per day, while the roofs will yield 2728 gallons under a 
24-inch per annum rainfall, — rather in excess therefore of what 
is required. Again, a gentleman's house in the country, with 
gardens, greenhouses, and stables, requires from 25 to 30 gallons 
per head per day, on the average number of inhabitants, and 
10 gallons for horses and cattle, and 5 gallons for pigs ; the 
roof area would in such a case be quite inadequate. 
In the case of my own house, containing 16 individuals, but 
neither horses nor cattle, the area of all the roofs, including that 
of a gardener's cottage, amounts to 8500 square feet. The 
house is supplied by metre from a water company ; the average 
annual consumption is 17,700 gallons, which includes a good 
deal of water used in the summer time in the flower and 
kitchen gardens, which are furnished with 10 hydrants, but it 
does not include a considerable quantity, probably 4000 gallons 
per annum of rain water, which is collected in tanks and used 
lor washing purposes, on account of the extreme hardness of the 
pipe water. The roofs, at 24-inch rainfall, would yield 105,000 
