From the very dawn of civilization it has been the endeavour of man to get the required amount of precipitation at the proper time. According to Crowe, as a mystical art rain-making appears to be almost as old as man himself, but the methods employed for many centuries fell more in the realm of public relations than in the field of science.
Artificial precipitation does not mean precipitation from artificially created clouds. Science has not developed to that state when it may be possible to create artificial rain- giving clouds at the desired time and place.
As a matter of fact, artificial precipitation is a process whereby precipitation is procured by artificially saturating a special type of cloud. Artificial precipitation is, therefore, also called the artificial ‘seeding’ of the clouds. It may also be referred to as artificial ‘modification’ of clouds.
Clouds consist of tiny droplets of water which are generally so light in weight and small in size that they are withheld by the updrafts of air in the atmosphere. Such microscopically small cloud-droplets are not capable of falling on the surface of the earth.
But when these cloud particles by various processes coalesce and grow larger in size, they start falling on the ground in the form of precipitation.
Therefore artificial precipitation involves the joining together of microscopic cloud particles so that they may grow in size and ultimately fall to the ground by their own weight.