Gwen took her wand in to her hand again and pointed it in to her watering can.
"Aguamenti." It quickly filled up with water. Then Gwen did the twist and tap movement, saying, "Chaudensis."
Gwen poured a few drops of hot water in to the pot, pauses, and then added more. She did this until she felt she'd given it just enough water.
"Professor Bentley, I'd like to mark my pot, but I'm not sure how."
This was one of the moments Gwen thought it would be helpful to have a permanent marker with her, something wizards and witches never seemed to have invented.