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FireworksDate: Period:

  1. The most important ingredient in gunpowderis the compound , more commonly known as “salt pepper”.
  1. Ancient alchemists refined the recipe to 75% potassium nitrate, 15% , and 10% . The ingredients become explosive after they are ground together.
  1. Black powder is a mixture of three components: potassium nitrate, sulfur, and charcoal. If you mix them together you end up with a in which you can still see the white, yellow and black flecks.
  1. If you take the same black powder but compress it into a tube, what we get is a little fountain. It only burns on the surface.
  1. Roman candles and fountains come from .
  1. The fireworks capital of the U.S. is , Pennsylvania, population of 30,000. Here fireworks are made by hand.
  1. The Italians developed almost all the basic fireworks we are familiar with. In the 19th century, one challenge still stood between the alchemists and total mastery of their art - color. They could make gold, they could make , they could create sparks, but their were terrible, weak, insipid, almost non-existent.
  1. In the 1830’s, pyrotechnicians made their breakthrough. They replaced potassium nitrate with potassium , a more energetic source of oxygen.
  1. This sped up the rate of oxygen delivered to the reaction, boosting the temperature of combustion from 1700C to C. This opened the door to a whole new set of chemicals that burned more fiercely and produced more intense colors.
  1. The modern firework display is full of color. You make color by adding salts to the composition.
  1. If you put a piece of copper into a fire, it glows with a flame. Adding strontium salts makes a red flame. Adding to the mix makes a green flame.
  1. The color spectrum is like a rainbow. The metal salt with the longest wavelength is strontium and appears and copper salts have a much shorter wavelength and appear .
  1. If no salts are added, the fireworks reflect all the colors in the visible spectrum and appear bright .
  1. Once the black powder charge in the bottom of the shell has been ignited it burns extremely quickly. Within 15 ms it generates large amounts of , blasting shells into the sky miles an hour.
  1. These fiery bombs usually travel 100 feet vertically for every inch of their diameter, so a 6-inch shell will shoot up to feet before exploding. The same shell might produce a burst of as much as feet across.
  1. Would be Pyroboys should be warned not to try this at home. Each year more than people in the U.S. suffer injuries resulting from the personal use of fireworks.
  1. In Lima, Peru, illegal fireworks set off an inferno that killed about people.
  1. Wind conditions that might blow a shell off course are also factored into the safety zone. If winds are stronger than miles per hour, it’s just too dangerous and the show stops.