Nigel was standing up now and felt it would be counter productive to sit back down and continue using the spells. He decided to do the spells in reverse order just for the fun of it and because he was already by the windows. Why making an unnecessary second trip. It was the smart thing to do.

"Vitrumonia!" Nigel cast at the first dirty window he saw. He was really liking this spell. He was thinking of casting it in his dormitory when he got back. There were some dirty windows there. Plus no of us clean them.

Nigel was just about to cast again when out of the corner of his eye he sees a gryffindor slip. It was pretty funny. But this was not the time to laugh at something like that. So Nigel went back to his dirty windows. "Vitrumonia!"

Now that was one clean window.