87 Lighting Our World-Mid

Lighting Our World FOCUS Question What problems did people need to solve to create safe indoor lighting?

为了创造安全的室内照明，人们需要解决哪些问题?

Fire and Flame Click! With just the flick of a switch, a room is awash in clean, bright light. It wasn't always this easy to banish darkness from homes and other buildings. Years ago, lighting up people's lives was often messy, smelly, and downright dangerous business. In prehistoric times, humans relied on wood fires to keep warm and as their primary source of light after sunset. A fire was located near the front of a cave. This placement provided a steady flow of air to feed the fire and allowed most of the smoke to flow out of the cave.

火和火焰点击!只要轻轻按一下开关，房间就会沐浴在干净明亮的光线中。 把黑暗从家庭和其他建筑中驱逐出去并不总是那么容易。 多年前，点亮人们的生活通常是一件混乱、难闻、完全危险的事情。 在史前时代，人类依靠柴火取暖，并将其作为日落后的主要光源。 在一个洞穴的前面附近有一处火。 这个位置提供了稳定的空气流来助长火势，并允许大部分烟雾流出洞穴。

When people began living in enclosed structures, fires moved inside. The fires continued to provide light. But now people had to get smoke from fires out of the structures safely. Chimneys helped, but since warm air rises, chimneys also let heat escape. Early structures did have windows to let in light. Most windows were simply open holes in walls that also let in weather and insects. Glass used for windows was not produced until the late Middle Ages, and even then it was quite expensive. When cold or storms set in, residents would cover their windows with animal skins or wooden shutters. These protective coverings had thin slits cut into them to allow some light to enter without exposing occupants to the elements.

当人们开始住在封闭的房子里时，火就会往里面移动。 火继续提供光亮。 但现在人们必须把火灾产生的烟雾安全地排出建筑物。 烟囱起到了一定的作用，但由于暖空气上升，烟囱也会让热量流失。 早期的建筑确实有窗户让光线进来。 大多数窗户只是墙上开的洞，也让天气和昆虫进来。 用于窗户的玻璃直到中世纪晚期才生产出来，即使在那时，它也是相当昂贵的。 当寒冷或暴风雨来临时，居民们会用兽皮或木百叶窗遮住窗户。 这些防护罩上有细缝，允许光线进入，而不会使居住者暴露在自然环境中。

Portable Lighting Handheld torches made of straw were the first portable lights. They could be carried from place to place but burned quickly and were smoky. Candles made of beeswax or tallow, a type of animal fat, lasted a bit longer and were less smoky, but they were costly. Many people instead used rushlights made from reeds soaked in animal fat and fastened with a clip to a metal stand. People discovered that animal fats and plant oils were more efficient and long-lasting than wood or reeds. In ancient Greece, people used simple clay lamps filled with olive oil. Over time, other oils, such as whale oil, were used in lamps.

用稻草制成的手持式手电筒是最早的便携式灯。 它们可以从一个地方带到另一个地方，但燃烧得很快，而且烟雾弥漫。 用蜂蜡或动物脂肪(一种动物脂肪)制成的蜡烛寿命长一些，烟味也少一些，但价格昂贵。 许多人转而使用用浸过动物脂肪的芦苇制成的灯芯草，并用夹子固定在金属支架上。 人们发现动物脂肪和植物油比木头和芦苇更有效、更持久。 在古希腊，人们使用简单的粘土灯，里面装满橄榄油。 随着时间的推移，其他油，如鲸油，被用于灯具。

In the mid-1800s, kerosene and natural gas became available. They burned easily and were cheap and plentiful. Kerosene lanterns produced less smoke and burned much hotter and brighter. Unlike a whale oil lamp, a kerosene lantern's flame burned inside a protective glass globe. Kerosene lanterns could still be dangerous, though. Heat from a lantern could ignite flammable materials nearby. Wooden buildings were especially vulnerable to fire. Do You Know? The Great New York City Fire of 1845 and the Great Chicago Fire of 1871 may have been ignited by kerosene lanterns.

19世纪中期，煤油和天然气开始供应。 它们容易燃烧，价格便宜，数量多。 煤油灯产生的烟雾更少，燃烧起来更热更亮。 与鲸油灯不同的是，煤油灯的火焰在一个玻璃保护罩内燃烧。 尽管如此，煤油灯仍然很危险。 灯笼发出的热量可能会点燃附近的易燃物质。 木制建筑尤其容易受到火灾的伤害。 你知道吗?1845年的纽约市大火和1871年的芝加哥大火可能是由煤油灯引起的。

The Glow of Gaslight Soon, natural gas was used to fuel outdoor streetlamps. Then it was piped inside to illuminate building interiors. Gas flowed directly to light fixtures permanently attached to multiple walls in each room. There was no need to carry lamps or lanterns from place to place. This method was an improvement over kerosene lanterns. However, burning gas at too low a temperature produces carbon monoxide, a toxic gas that can slowly suffocate people. And a room full of leaking gas could explode from the smallest spark!

煤气灯的光辉很快，天然气被用来作为室外路灯的燃料。 然后通过管道进入室内，照亮建筑内部。 气体直接流向固定在每个房间多面墙上的灯具。 没有必要提着灯从一个地方到另一个地方。 这种方法是对煤油灯的改进。 然而，燃烧温度过低的气体会产生一氧化碳，这是一种有毒气体，会慢慢使人窒息。 一个充满煤气泄漏的房间可能会因为最小的火花而爆炸!