646 
Cottage Sanitation. 
surface around. This can be remedied by lining the intei’ior of 
the well from the rock surface upwards with a coating of cement 
or concrete, and surrounding the mouth of the well with a small 
coping. 
Artesian loells . — In some parts of the country artesian wells 
can be bored at no great cost. The water from these is at its 
origin free from contamination, but needs to be guarded like 
other wells from pollutions near the surface. 
Fig. 11.— Sliallow well fouled by surface water and by soakagc from manure lieap and pigsty. 
It is often the duty of the sanitary authority to sink deep 
wells for cottages, and they will in some cases find it least expen- 
sive to bore an artesian well. 
(4) Rain water. — In many parts of the country where the soil 
is porous and of great depth there is no good water supplj^ avail- 
able except that from rain. At a distance from towns this is of 
great purity. Tlie average amount that falls on the roof of a two- 
