Eraser - History

History

Before rubber erasers, tablets of rubber or wax were used to erase lead or charcoal marks from paper. Bits of rough stone such as sandstone or pumice were used to remove small errors from parchment or papyrus documents written in ink. Crustless bread was used as an eraser in the past; a Meiji-era Tokyo student said: "Bread erasers were used in place of rubber erasers, and so they would give them to us with no restriction on amount. So we thought nothing of taking these and eating a firm part to at least slightly satisfy our hunger."

On April 15, 1770, Joseph Priestley described a vegetable gum to remove pencil marks: "I have seen a substance excellently adapted to the purpose of wiping from paper the mark of black lead pencil." He dubbed the substance "rubber".

In 1770, Edward Nairne, an English engineer, is credited with developing the first widely-marketed rubber eraser for an inventions competition. He sold natural rubber erasers for the high price of three shillings per half-inch cube. According to Nairne, he inadvertently picked up a piece of rubber instead of breadcrumbs, discovered rubber's erasing properties, and began selling rubber erasers. Incidentally, that was the first practical application of the substance in Europe, and rubbing out the pencil marks gave it its English name.

However, raw rubber shared the same inconveniences as bread, since it was perishable. In 1839, inventor Charles Goodyear discovered the process of vulcanization, a method that would cure rubber and make it a durable material. Rubber erasers became common with this advent of vulcanization.

On March 30, 1858, Hymen Lipman of Philadelphia, USA, received the first patent for attaching an eraser to the end of a pencil. It was later invalidated because it was determined to be simply a composite of two devices rather than an entirely new product.

Erasers may be rectangular blocks (block and wedge eraser), or conical caps that can slip onto the end of a pencil (cap eraser). A barrel or click eraser is a device shaped like a pencil, but instead of being filled with pencil lead, its barrel contains a retractable cylinder of eraser material (most commonly soft vinyl). Novelty erasers, in a dual role as figurines (such as musical notes, animals, confectionery), are mostly decorative, as their hard vinyl tends to smear heavy markings.