You'd think that the answer to this question would be a simple one. I'm sure you're thinking, "They take away the marks, Dummy." Well you are right, they do. But do you know how? Basically, the molecules in the rubber attract the graphite from the paper because they are stickier than those of the paper. Personally, I think it is because the molecules are friendlier. :)
In the case of the eraser that the Palmers have used for over two hundred years, well that eraser is not friendlier at all. In fact, it is far from that. This erasier is so mean, it repels. People of course, not graphite. This square of rubber, for all practical purposes, should be considered much more. Yes, much more. As a nuke in an arsenal it deters. Teddy Roosevelt would have considered it a "big stick" if he'd have owned it. It seems the Palmers took to heart the President's famous saying, "Walk softly and carry a big stick", in regards to this eraser. They knew its power and so did those that feared it.
All because erasers take away "marks".