Minute crystals of silver iodide produced in the form of smoke acts as efficient ice forming nuclei at temperatures below -5°C to produce enormous number of nuclei (1015 per gram of silver iodide). When this smoke is introduced into super-cooled cloud, some ice crystals appear when temperatures fall below -4°C, but its formation rapidly increases with decreasing temperatures. Cloud seeding by silver iodide is done either from ground generators or from airborne generators. Substances other than silver iodide as artificial nuclei are lead iodide, cupric sulphide, cupric oxide, ammonium fluoride, cadmium iodide and iodine. However, all these are not as effective as silver iodide.
A. Bowen reported there were six, and several railroads said they would cheerfully render full transportation free of charge. But he also recommended the use of balloons instead of mortars. He called on several gentlemen under the charge of noted rainmaker General Robert G. Dyrenforth to meet with the Board and discuss arrangements using that method (The Daily Light, 1892). On November 14, 1892, the Board was pleased to receive and make welcome Messrs. John H. King and John H. Dickinson, who gave an account of their experiments under General Dyrenforth. They advised the Board it was not necessary to discuss the importance of this work, because if rain can be produced at will, land values will be raised by 300 percent. They told how they had received an appropriation from Congress and had been conducting experiments in South Dakota, but "the government was too slow, and the western people had become interested, so they were here, with their balloons, power, and other apparatus in Galveston ready to be sent, and now they wanted the citizens of San Antonio to come to the front and help by a kind word and a small subscription." The Board passed a resolution heartily recommending their work to the citizens of San Antonio.
Following the games, china officials admitted that the weather was out of their control and attributed to a 2009 blizzard to their own handy work. This shows that we’re not ready for cloud seeding or any other kind of weather modification. This also is an example of how cloud seeding has long-term effects.
"Rainmaking experiments: progress for the arrangements of carrying on operations", San Antonio Daily-News, April 29, 1892.
"The rainmakers: an important meeting held and arrangements made to experiment", San Antonio Daily Light, November 14, 1892.
"The rainmakers welcomed", The Daily Light, November 15, 1892.