Ravi is absolutely right. But during our time our Art Teacher was Lady Temple. Mr. Hazarnis used to also help Mr. Ranji in the carpentry room, the backroom of which used to be the teachers secret smokers hangout.
I had this in response from Ravi:
It is interesting to see how each cohort at Cathedral had slightly different experiences. By our time, the art room (and Hazarnis) relocated to just under the further turret (reached by an inside staircase) above the physics/chemistry labs. I don't think he "descended" very often from the very top of the building.
In our time the Art Room was the Library, which we went to from the gym via the staircase at the side of the boxing ring! It was also the room where we used to have the lunch if we bought the school lunch. I tried it, the lunch, for a couple of months, learnt a lot about table manners from that experience, but the quantity hardly filled a small corner of my stomach!
Thanks for that input, Ravi! Certainly made my brains do a little bit of work.