In reference to the history teacher, I’m fairly sure she would not be lying to her pupils why would she? I’m also fairly sure and I don’t want to burst Phillips bubble, that she would not have been slippered on her bare bum, the reality probably would be more like, touch your toes girl, and then simply a, whack, whack, whack, across the back of her school skirt, with the occasional Ouch from her, and probably a bit of frantic rubbing afterward.
Also the stocking and suspenders, pigtails, etc. are probably wishful thinking on his part, but who knows they were popular at the time, as were very short skirts so perhaps the headmaster wouldn’t even need to lift her skirt, although I very much doubt that a fifteen-year-old girls knickers came down at school, very unlikely that any girls was spanked bottom beyond primary school. Im also guessing that the slipper in question would have actually been a gym shoe as oppose to a leather slipper, as this was the usual type of slipper at schools.