Over the past fifteen years, meteorologists have learned a great deal about clouds and precipitation. Many of the mysteries of thunderstorms, tornadoes, and cyclones have been uncovered. Radar has played an important role in this progress. Along with the instrumented airplane, capable of making detailed measurements in the free air, radar brought to the hands of atmospheric scientists large quantities of new observations to permit better descriptions of many kinds of weather phenomena.
Another instrumental triumph of the last twenty years, the high-speed electronic computer, has made it possible to solve some of the complex equations that describe atmospheric processes and predict future weather. The computer has helped to unravel problems that would have been completely unmanageable in the forties.
Probably the most important development in meteorology in the last two decades has been the rise in the number of highly competent scientists who have joined in the study of the atmosphere. The great ad-