Ha, trust the Hufflepuffs to think it's easier and more sensible to move a whole group of people up in the air than it is to just knock some mortar down. They never said the column had to stay upright, did they!

We used blasting spells on the mortar until the top of the tower was crumbled at our feet. Wasn't much more than dust and chunks by then, but the examiners said it was a fine job.