The coin will not work unless he is holding it.
The first coin apparently didn't work because he hit the box with the flat of his hand and tried again.
These are usually represented by green stones, but coins work just as well.
If the coin is working again, then surely you can command some machine to take us away.
"But you can't deny the coins work," said Jonathan, "or that the watch stops things short."
A screwdriver, knife, coin, or anything metal will work.
The New Jersey coins will not work in the subways, which have different mechanisms than the bus fareboxes.
The coin will still work, I think.
As he approached the bridge on his return trip the following day, he worried that the Canadian coin might not work in the exact change machine.
He and his coin worked overtime.