Nuns in Catholic schools used a ruler, according to several older Catholics I know. Here in Texas, once upon a time, teachers were allowed to use a paddle.

I am not a believer in corporal punishment but there need to be consequences for bad behavior. Part of the problem, from friends of mine who are teachers, is that parents refuse to back up the teacher.

Once this was not the case - if a child was misbehaving, and the parents were called, the problem was usually dealt with by the parents.