The individual left in the office had to draw all the curtains (it was a ground-floor office) to ensure privacy – though I recall that the windows remained open in the summer so people outside could hear if they were passing. Not that that was on our minds at the time. While the curtains were being drawn, the headmaster would buzz (he had one of those early intercom systems on his phone, I’m not sure when he got this, I don’t think it was there in my first year, but was certainly there by 1976), the secretaries and ask them to bring him a cane and the book.
I hated the wait outside and hearing other people getting caned and would have preferred to be first.