Hi, Rusty!
I didn't see "a toll" as meaning "a ring"!
Well, I was almost there...."atoll" does mean "ring-shaped"!
I understand the parsing of "Melbourne," now that you have kindly explained it to me.....but I would never have got it by myself!
Yes, I think you are right about Melbourne's derivation.
Originally, the Australian town was called Batmania after John Batman, but then was renamed after Lord Melbourne.
William Lamb's seat here was Melbourne Hall in the market town of Melbourne in Derbyshire.
But i am unsure how Melbourne in Australia came to be named after him?
I wonder if it were because he was a mentor to Queen Victoria.......and she consequently chose the name?
I shall have to look this up........