Originating in the Far East, extravagant displays of fireworks are now used to celebrate many special occasions throughout the land. The ones within this cauldron are renowned for exploding in colorful displays high up in the air. The wizards are doubling their efforts, toiling and troubling over how to get them to work.
The Firework Cauldron's description states, "doubling their efforts, toiling and troubling over how to get them to work". This is likely a reference to "Double, double, toil and trouble; Fire burn and cauldron bubble", a line in Shakespeare's "Macbeth".