Some pictures

 Looking to this 3 pictures you may think that the IR was a dark period because of the pollution. If you are thinking this you are correct. There was a lot of pollution and people had few life expectancy. This was caused because of the long working periods of 12 hours, no rests and because they started very young, as a child to work.
 The buildings were big factories and if you are in a big mountain and you looked at the city you saw a lot of chimneys throwing smoke and you couldn´t see any building.