FORECASTING THE WEATHER
Systematic weather forecasting by technical methods has been practised for about a century. The early success depended on the development of the "electric telegraph" and has throughout gone forward with the improvements in rapid communication, the telegraph, the telephone, radio, teleprinter, radio-teleprinter, facsimile transmission, television. The possibility of forecasting beyond a few hours ahead in changeable weather arises simply because the weather systems, especially depressions and anticyclones, move slowly across the map, admittedly changing their structure as they do so but broadly carrying their typical weather conditions with them.