One of the things about any big city is that it gets dirty. You know how much grime builds up in our own time, even with giant mechanical street sweepers.
Now imagine living in London in the early 1800s. No giant mechanical street sweepers. There are carriages pulled by horses, cattle being driven through the streets, gentlemen on horseback and all of that leads to dung everywhere.
So what do you do if you are a young lady in a long dress? One option is to hire a crossing sweeper. These young men, usually little more than boys really, would wait at intersections with rough brooms and offer to clear a path for a small fee. Some of them had little bridges that they’d roll into place.
Here’s how that looks in Without a Summer.
With stout half- boots, the puddles and refuse on the walks offered no real concern, though Jane did pay sixpence to a crossing sweeper at one particularly foul intersection. She let Melody guide their stroll, caught up in her sister’s enthusiasm for the wealth of opportunities provided by London.
In the background of this illustration, you can see that even the gentleman is picking his way across the river of filth running down the middle of the street.
For further reading, may I recommend the post on Jane Austen’s World, “Oh What a Stench.”