April 15, 1770 — Joseph Priestley recorded his discovery of a item made from rubber imported from Brazil that would erase — “rub out” — pencil marks. Priestly wrote, “I have seen a substance excellently adapted to the purpose of wiping from paper the mark of black led pencil.” Priestly called his new product a “rubber”:
Information sources for Rubber Eraser Day:
http://inventors.about.com/od/pstartinventors/a/JosephPriestley.htm
http://en.wikipedia.org/wiki/Joseph_Priestley
http://www.holidayinsights.com/other/rubbereraserday.htm
April 15 is also “Tax Day” in the U.S. — the due date for individual income tax returns. Many erasers are used to get the tax as low as possible.