MISCELLANEOUS

dated August 10 and 11, 1953: Artificial Rain

Experiments in the making of artificial rain had not till then produced practically significant results, said Prof. T. N. Seshadri, speaking under the auspices of the Lakshmipuram Young Men's Association, Royapettah, on the 9th. He wanted an objective scientific assessment of artificial-rain-making to be conducted by experts. Some fantastic claims had been made about results of experiments on artificial rain-making, but the days when they could get rain to order had not come in fact, those days were far off; the little success achieved was not of practical significance. Artificial rain-making had attained great importance owing to the repeated failure of the North-East monsoon. Explaining the nature of clouds, the Professor said cirrus clouds which one could see on a fine day about 30,000 feet high were not rain clouds; then there were stratiform clouds between 20,000 and 10,000 feet from the ground. Cumulus clouds with flat base and dome-like top were comparatively nearer to the ground and offered the best chance of success for inducing rainfall. The water particles in such clouds was of the order of 1/10,000 of an inch in diameter. Rain could fall only if the tiny droplets of water condensed into bigger drops having a diameter of at least 1/100 inch. About a million droplets had to coalesce to give one drop of rain.