What's that strange device and how do I use it?

You've been gathering pieces of it from all over the island (and all across time).

Is it assembled now?

If not, get your final piece from Gio's Apothecary.

Have you found the instructions on how to use it?

If not, reveal the invisible notices on the BULLETIN BOARD.

The instructions are clear: don't use it before you've talked with your ally.

Have you talked with your ally yet? If not, return after you have.

So first you're supposed to dunk the device in fresh WATER. Just once this time.

Tap the fountain for a closeup and gently lower your device into the water.

In step 2 you're supposed to add "Cu."

Cu is the chemical symbol for copper.

Do you have anything made out of COPPER?

Drop the BAG of pennies into the fountain.

A display on the device seems to indicate that you need a little more copper.

Do you have anything else made out of copper?

Something you've been carrying with you for ages without even knowing why?

Drop the DOORKNOB into the fountain.

Congratulations, you are now thrown out of the bubble! Use your time well!