My intention was to make it hurt more, certainly, but also to send a clear message to these boys and to others who heard of it that what they had done was absolutely unacceptable.
I can’t say why other teachers have done it. I have to say the idea of doing it to see where the cane landed doesn’t make a lot of sense to me. I only did it a few times but I really do not recall marking appearing fast enough to give me instant feedback. In a case where I gave a boy more than six strokes, by the eighth and ninth strokes, I could see that I was causing damage that was unacceptable to me but that is how long it took for marking to form.