I recall a series of young adult or children book, but cannot find the name about a group of boys who solved a detective club of sorts. They solved mysteries or other problems in their community.
- In one book, they helped solve a case involving a missing treasure that was placed in the barrel of a cannon.
- In another book, they bought a submarine, by bidding down instead of up, and used it to explore a local lake.
- In another book, they helped locate a lost parachute jumper.
Does anyone know the name of this series?