Presentation on theme: "nitroglycerine invented"— Presentation transcript:
1 nitroglycerine invented 1815Davy lamp invented1875Gelignite invented200 BCEChinese use gunpowder1847nitroglycerine inventedClick on a box to find out more about each development in the history of explosives.1866Invention of dynamite
2 The Chinese invent gunpowder Gunpowder was invented about 1200 years ago.It was used for warfare.For a long time, it was the only explosive available.Gunpowder is not very powerful and needs to be lit with a flame.The explosion goes through the powder at 60 m/s.Gunpowder is still used in fireworks.
3 The dangers of mining and the Davy lamp Exploding natural gas was a problem for miners in the eighteenth century. While cutting away at the coal, large amounts of methane were often released which exploded due to the high temperatures of the flames in the lamps the miners used.In 1815, Sir Humphry Davy invented a safer mining lamp which was called the Davy lamp. A wire mesh around the flame inside the lamp conducted heat away from the flame making the surrounding air less hot. This stopped the natural gas exploding.
4 The invention of nitroglycerine Ascanio Sobrero, an Italian scientist, invented nitroglycerine in 1847.It is very dangerous as it can explode even if it is only knocked slightly. Chemicals like this are described as ‘unstable’.An explosion spreads through nitroglycerine at 7000 m/s.
5 The invention of dynamite In 1865 Alfred Nobel opened a factory to make nitroglycerine. The factory blew up, killing his brother.Nobel went on to invent a more stable form of nitroglycerine by soaking it in a type of clay.This new explosive was called dynamite.Dynamite is still used today. There are also many other explosives which, like dynamite, are very powerful but also very stable.
6 Gelignite inventedGelignite was invented by Alfred Nobel, after he had invented dynamite.Unlike dynamite, gelignite cannot explode without a detonator and so can be stored more safely.Gelignite is a type of ‘plastic explosive’. This doesn’t mean they are made out of plastic! The description refers to one of their properties – they can be moulded into shape.