82 Creating Those Shooting Stars

Gazing into the sky on a hot Fourth of July evening, you probably react with pleasure and sometimes even astonishment at the lovely fireworks spectacle you are witnessing. You may not, however, give too much consideration to the origins, or the makings, of the show.

Opinions differ as to who actually produced the first fireworks; most commonly they are attributed to the ancient Chinese, and the credit for introducing them to Europe is given to 13th-century explorer Marco Polo. The composition of fireworks as it exists today was essentially established by the early 1800s; but more primitive versions of fireworks accompanied weddings, festivals, military victories, and other celebrations for hundreds of years prior to that.

The basic ingredient in all fireworks is what is known as black powder, a mixture of saltpeter, charcoal, and sulfur. This is combined with various coloring and binding agents to make a doughlike substance that is cut into small lumps called stars. The stars, which are very volatile, are packed together with loose black powder, which explodes more slowly, into easily burned containers known as shells. A large shell may hold as many as 100 stars and, depending on how it is packaged, may burst into numerous fireworks when propelled into the air.

Fireworks must be handled with great caution. Since stars may explode if exposed to even static electricity, manufacturers must wear cotton rather than synthetic clothing when they work. Igniting fuses must be timed exactly so that shells don’t detonate too close to the ground. Pyrotechnics is a very precise art, and the wise technician maintains a healthy respect for it.

82 制造那些流星

在炎热的7月4日夜晚仰望天空，你可能会为眼前绚丽的烟花表演感到愉悦，有时甚至惊叹不已。不过，你或许不会太在意这场表演的起源或制作过程。

关于谁最早发明了烟花，人们意见不一；最普遍的说法是古代中国人发明了烟花，而将其引入欧洲的功劳归于13世纪的探险家马可·波罗。如今烟花的配方在19世纪初基本定型，但更原始的烟花在此之前的数百年里，就已经出现在婚礼、节日、军事胜利及其他庆典活动中了。

所有烟花的基本原料是黑火药，由硝石、木炭和硫磺混合而成。黑火药与各种着色剂和黏合剂混合，制成类似面团的物质，再被切成小块，称为“星粒”。星粒的挥发性很强，它们与燃烧较慢的松散黑火药一起被装入易燃的容器（称为“弹壳”）中。一个大弹壳可以装多达100颗星粒，根据包装方式的不同，被发射到空中后可能会爆发出大量烟花。

烟花的处理必须极其谨慎。由于星粒即使接触到静电也可能爆炸，制造商工作时必须穿棉质衣物而非合成纤维衣物。引信的点燃时间必须精确把控，确保弹壳不会在离地面太近的地方爆炸。烟火制作是一门非常精密的技艺，明智的技师会对它保持应有的敬畏。