Shaking Loose the Rain
"Years ago pioneers believed that rain followed the plow; the evaporation from land surfaces and the conservation of run-off water caused a proportionate increase in the rainfall. After the cycle of wet years had passed, the dry nineties brought ruin to farmers in semi-arid regions. Another theory held that the source of Nebraska's rainfall was largely in local evaporation, and not from the Gulf of Mexico. This was soon abandoned. Then, in the nineties, came the "rain doctors," who set off explosions on high hills to jar loose the moisture they believed was in the air. This was also a failure. The only think left was to pray for rain. And even the practice of holding prayer meetings for rain was not always successful."
1939 Almanac for Nebraskans, p. 63 (NSHS 7294-7009)