As the laws of health become better understood, greater precautions are
taken to prevent sickness. For years all evidence has been pointing to
drinking water as a common source of most diseases and the principal
means of spreading sickness. Every well, spring and cistern, open
to surface water or walled and covered with materials through which
surface water can seep, is liable to contain disease germs. Concrete
walls and covers are water-tight: they afford perfect protection for
both man and beast.