Victorian London: The Tale of a City from 1840-1870, by Liza Picard
The premise is basically all the interesting facts of daily life in London that Picard could find. She chose to focus on thirty years of the Victorian era just to narrow it down.
So far, I've read about the smells (too horrific to be believed), the water sources, most importantly the River Thames, the roadways, and the houses of the period, including the bathrooms.
For years before a flushing toilet was invented, they used what is known as an earth closet, where you would do your business in a hole in the bathroom and shovel fresh dirt over it in order to make fertilizer. Quite interesting.