One possible reason for Swedish engineer Alfred Nobel's invention of dynamite was the safety of construction work and blasting rock in the mid-1800s. Nobel helped build bridges in Stockholm. Nitroglycerine was used in the detonation of rock, and it was a relatively unsafe method. According to the Nobel Prize Organization, Alfred Nobel's brother Emil was killed in a nitroglycerine explosion.
Italian chemist Ascanio Sobrero invented nitroglycerine about 20 years before Nobel's patents, but in a liquid state, the explosive is very volatile. Through his research, Nobel found that mixing nitroglycerine with a fine clay transformed the liquid into rods capable of being placed directly into holes. Along with the pneumatic drill, blasting rock became much safer and more profitable.
Nobel invented the blasting cap, also known as the Nobel patent detonator, in 1863. This detonator relied on shocks rather than heat to ignite the explosive. Nobel received his U.S. patent for dynamite in 1867 and later patented a blasting gelatine. Beginning in 1864, Nobel founded several dynamite factories across Europe and exported dynamite to the United States and Australia.
Before his invention of dynamite, Stockholm actually banned experimentation with nitroglycerine within its city limits. Nobel worked in various countries including Germany, Scotland and Italy in order to develop the safer form of explosive.