In the early 1850s, "Punch" journalist Henry Mayhew began visiting London's poverty-stricken East End and documenting the lives and careers of folks eking out their livings on starvation's edge.Link (Thanks, Kim!)
These in-their-own-words descriptions of daily toil are all the more fascinating for the ingenius services provided. Want an exotic bird? A clever con-artist will hand paint a drab domestic peeper, which will sing in your window until overwhelmed by its toxic coat. Or perhaps you require chemicals with which to tan leather? Just hire an old lady to come by every few hours with a can full of dog crap, the #1 substance for the job. (This was one of the better paying occupations of the lower classes.)
The University of Virginia has digitized Mayhew's rare and fascinating work, illuminating the secret histories and practices of costermongers, ginger beer men, love song sellers, lucifer match dealers and all their colorful, forgotten peers.
Update: Phil sez, "Further to your post about the University of Virginia digitising Henry Mayhew's excellent 1850s accounts of London's poor... They only appear to have the first volume. Tufts have had the full four volumes available online for at least a couple of years. They also include scans of images from the books -- example.
"In case the full volumes are a bit daunting, I blogged a couple of my favourite extracts a while back, one about a man fighting rats for money (with his mouth!) and one about the hilarious tricks early photographic shops used to get up to with customers who weren't accustomed to seeing photos."