A century ago Thomas Edison had not yet invented the incandescent lamp to bring light to many dark places of the earth.

一个世纪以前，托马斯·爱迪生还没有发明给地球上很多黑暗的地方带来光明的白炽灯。

Similarly, you may have noticed that when you sit in front of an incandescent lamp for too long, it feels warmer than the rest of the darkroom.

同样，你可能已经注意到，当你长时间坐在白炽灯前时，会感觉比暗房的其他地方更暖和。