The August 10, 1973 newsletter by Henry Lansford announces the end of the 1973 field research. Although there were few hail storms to seed, much data was gathered by aircraft and radar. The experiment is planned to run for three more years in order to obtain enough data to determine the cloud see... Show moreThe August 10, 1973 newsletter by Henry Lansford announces the end of the 1973 field research. Although there were few hail storms to seed, much data was gathered by aircraft and radar. The experiment is planned to run for three more years in order to obtain enough data to determine the cloud seeding efficacy, which is as of yet inconclusive. Show less