Today's anniversary of the pencil eraser

On today's date, 1858, Hymen Lipman was granted a patent for attaching a piece of rubber to the end of a pencil. While it was certainly a stroke of genius, the courts didn't think it to be as groundbreaking as one might think. From Smithsonian:
Unfortunately for Lipman, the patent would later be revoked, when the U.S. Supreme Court rules in 1875 that a pencil with an eraser is just a pencil with an eraser and not a new invention.
Hymen L. Lipman makes his mark in pencil history

For more than you ever wanted to know about the history of the pencil, don't miss Henry Petroski's book The Pencil: A History of Design and Circumstances.