Weather balloons

1749
British scientists use thermometers attached to paper kites to sample atmospheric temperature up to about 1,000 feet.

1896
French scientist Leon Teisserenc de Bort carries out experiments with high-flying instrumental balloons. In 1902, after making 236 flights, he announces that the atmosphere comprises two layers - the troposphere and the stratosphere. In the UK, English scientists WH Dines and WN Shaw conduct experiments with meteorological kites.

1914-18
Winged box kites designed by Samuel Franklyn Cody are used for surveillance work (artillery spotting and general observation). When 'stacked', and with a basket attached, they can easily carry a man aloft. Observers record the weather details existing above ground. Tethered military kite balloons are also used - wind data from around 1,500 feet are required for their deployment.

1919
Finnish Professor Vilho Väisälä introduces improvements to the kite method of studying the atmosphere and, making use of variable capacitance, designs additional instruments for the purpose.

1931
The first radiosonde 'flight' takes place, further development follows. In 1935 the new device is presented to the meteorological community, and the following year it is accepted for routine use in Scandinavia. It is simple, reliable and moderately priced. With mass production they go 'international, and the first deliveries are made to the USA.

1939
The UK adopts the radiosonde at the start of World War II. The somewhat bulky package of sensors and battery is carried aloft by a gas-filled balloon, and data vital to weather forecasts and military operations are transmitted to receiving stations on the ground.

1946
In the post-war years the advent of many international programmes sees a rapid rise in the use of radiosondes.

1976
The world's first fully automatic, computer-controlled upper-air sounding systems are introduced in the UK by Väisälä of Finland.