Water wells are important to all societies, providing reliable supplies of water for homes, irrigation and industries. Since humans cannot survive without ground water, it is little wonder that early cultures considered wells as sacred, and many believed they housed deities that could grant wishes - thus the origin of the wishing well folklore. Today, nearly 1 billion people struggle to find clean drinking water, and other water related issues. Hand-dug wells with buckets and ropes to retrieve the water are among the earliest inventions. Pulleys, rocker arms, and all manner of mechanical contrivances were fitted to the task as well. The difficulties of raising water from wells and draining mines stimulated research into the theory of the vacuum and the operation of pumps, leading to basic understanding of the atmosphere, pressure, and hydraulics. While the faucets of city dwellers do not reveal the ultimate source of their water, like rural dwellers, they rely on shafts drilled into the earth, through which are run pumps and pipes.