I used to have this book about 20-ish years ago.
- Setting for the story is some time around the gold rush
- Boy runs away from home (possibly an orphanage?), a man on a traveling wagon offers to hide him from searchers.
- The man turns out to be a "doctor" who sells a fake "cure-all" potion / elixir as a traveling snake oil salesman.
- They travel around, set up in mining towns and have a bit of a show, with the goal being to fleece people out of their money by selling the fake potions.
- One wagon contains a blind strong man who is forced to perform. I think there is at least one other member of the troop, but I don't remember any details about them.
- The boy is essentially held captive by some sort of threat, forced to learn juggling underneath the threat of a whip so that he can perform in the shows.
- Often they are chased out of town once the potions are found to be fake. At some point the show is exposed and there is a large brawl.
- Eventually he escapes and is chased by the "doctor". If I recall correctly, he carves a hole into the bottom of the wagon (locked for "safety purposes") and drops out onto the road. I don't recall if the strong man accompanies him.
- I believe the boy finds his father??
- I want to say it ends with them somehow owning a small mine that ends up having enough gold that they can live comfortably.
Hoping that's enough to identify this book, would love to read it again!
