 The poor walked, and might be splashed by the wheeled vehicles and drenched by slops being thrown out and water falling from the overhanging roofs.Another hazard was the choking black smoke belching forth from factories which made soap, from breweries and iron smelters and from about 15,000 houses burning coal.Outside the city walls, suburbs had sprung up providing homes for the craftsmen and tradespeople who flocked to the already overcrowded city.