Rain Makers.. CSIRO Radio Physic Rain Physic Group -- The New Avro Anson of the Rain Group working with a RAAF Dakota. On the wing of the Anson can be seen the silver Iodide smoke generator that sprays the clouds with the mixture.The usual process is to spray from the bottom it being lighten Pierces the clouds and causes the Rain to falls. The Anson will work from Wagga. August 18, 1955. (Photo by Gordon Herbert Short/Fairfax Media).