Pilot or pibal balloons were one of the first methods of determining the condition of winds-aloft. These balloon observations were useful to early aviators and were extensively used during World War I. Today it's the National Weather Service but back then it was called the Meteorological Service of the U.S. Signal Corps. In 1923 nearly 5000 pilot balloon observations were taken and were kept in sight at a distance of 60 miles and sometimes to heights of 20 miles. Before balloons, the first reliable observations of upper air winds came from instrumented kites. Benjamin Franklin initiated the use of kites for weather experiments and by the 1890s observations of the atmosphere were common place due to the development of steel piano wire. The wire supported the weight of the kite and the attached instrument packages. However, without the wind, the kite didn't soar and the balloon replaced it. Also...following the bombing of Hiroshima on August 6, 1945, which resulted in 140,000 deaths, the Makurazaki Typhoon hit the city one month later killing 1,200. The second bombing of Japan was scheduled on August 11 but was moved up two days due to expected bad weather and the originally selected city of Kokura was later changed to Nagasaki.  On August 9, 1945, a B-29 bomber, nicknamed Bockscar, after its commander, Frederick Bock, took-off from the island of Tinian carrying a 9,000 pound plutonium bomb named Fat Man with a blast equivalent of 21 kilotons of TNT.  Two weather observation planes scouted conditions over both target areas.  At 11:02 a.m. on August 9, 1945 the nuclear inferno was unleashed 500 meters above the surface.