while standing on the scaffold who caches hesters attention?
If you mean the 1st scaffold scene (there are 3), it's Chillingworth. However the narrator doesn't identify him right away but calls him the stranger and describes him as a white man, clad in a strange disarray of civilized and savage costume. He was small in stature, with a furrowed visage, which as yet could hardly be termed aged. There was a remarkable intelligence in his features, as of a person who had so cultivated his mental part that it could not fail to mould the physical to itself and become manifest by unmistakable tokens. It's only later that we find out that this is Chillingworth, Hester's husband.
