To me, it was almost like someone took a piece of a pocket watch chain, and possibly a coin and glued them together (and maybe with something else thrown in, I've never been sure).

Yeah, I just dubbed it The Fabulous Doohickey of Mesmerism.

(And something I thought about at one point: It might have been helpful if Jonathan had stolen it and run off with it, while he hid the thing under a convenient shrub for the sake of his Master. There might have been more than a glance at the thing then.)