Wednesday, March 30, 2011

Pencil Day

Hymen Lipman Pencil Patent
Innovation in the pencil industry

Today we celebrate the first patent on the modern pencil. There have been many innovations in pencil design or methods of production through the last several hundred years. March 30th, 2008 marked the 150th anniversary of a famous patent which was the first patent to address the installation of a rubber eraser at the end of a wood-cased pencil. The patent filed by Hymen Lipman of Philadelphia, PA was granted on March 30th 1858. An interesting feature of this design was that the eraser was actually installed within the wood of the pencil opposite from the writing core end. In this manner, the pencil could be sharpened on both ends to refresh either the graphite core or eraser.

As it turns out, there were countering claims from another inventor who developed the use of a ferrule to attach an eraser. Faber claimed these were not patentable innovations since pencil and erasers previously existed. The combination did not change the basic function of these two items. The case eventually went to the U.S. Supreme Court.

Pencils have been mass produced in Europe since 1622, but they weren't in production in the United States until 1812. Pencils began being painted yellow because it is a color often associated with royalty and honor. During this time, a yellow pencil became known as the best type of pencil you could buy.

Why are Pencils Yellow?
The true story behind the yellow pencil

Pencils have been painted yellow ever since the 1890s. During the 1800s, the best graphite in the world came from China. American pencil makers wanted a special way to tell people that their pencils contained Chinese graphite.

In China, the color yellow is associated with royalty and respect. American pencil manufacturers began painting their pencils bright yellow to communicate this "regal" feeling and association with China. However, according to Henry Petroski's history of the pencil, the European producer Koh-I-Noor was the first to paint one of their pencils yellow.

The rest, as they say, is history.


When was the pencil invented?
Some time prior to about 1560, graphite was discovered near Borrowdale, England, supposedly when a large tree was uprooted in a storm, exposing a black substance beneath its roots. The usefulness of graphite as a marking substance was quickly realized. Though the exact date is not known for certain, the year 1565 marks the first record of a pencil consisting of a piece of graphite inserted into a wood shaft, making the first ancestor of today's pencil.

Where was the pencil invented?
Since graphite was discovered in England, it is most likely that the first pencils were made in England, though this is not known for certain. The pencil was further developed by European craftsmen.

Who invented the first pencil?
It is not known who invented the first pencil. The pencil was first documented in 1565 by Conrad Gesner, and its invention is sometimes attributed to him, though this is unlikely. European craftsman (woodworkers) were the first known pencil manufacturers, and it wasn't until the late 1700's that manufacturing techniques similar to those practiced today were developed.

Why is the 'lead' so called?
Before the discovery of graphite, soft metals such as lead were often used for writing. One early name for graphite was 'black lead', and the name 'lead' has remained in use.

Can one get lead poisoning from pencil lead?
No. The 'lead' in lead pencils is actually graphite, which is a form of carbon and is non-poisonous.

What do the numbers and letters on pencils mean?
The numbers or letters refer to the hardness or softness of the lead. Read the article 'Grading Pencils' for more information.

What is a 'carpenter' pencil and why are they shaped so funny?
A carpenter pencil is usually a large, flattened pencil used by carpenters. Their shape helps prevent them from rolling.

How are pencils made?

The picture at left illustrates the steps involved in the manufacture of a wood pencil. 

It starts with a block of cedar (1) which is then cut into slats (2).
The slats are then stained (3) and grooves are cut into one surface (4). 

Prepared leads are placed into the grooves (5) and a second slat is placed on top and bonded with the first (6). 

This 'pencil sandwich' is then passed through a milling process (7) to separate the individual pencils (8). 

The pencil is painted and finished (9 & 10), a ferrule crimped onto the end (11), and finally, an eraser is crimped into the ferrule (12).

 Also On This Day:
 - The 1st recorded passing of Halley’s Comet (240 B.C.)
 - Florida became a U.S. territory (1822)
 - Anesthesia was used for the 1st time in an operation (1842)
 - Alaska was purchased from Russia for approximately $0.02 per acre (1867)
 - The 15th Amendment went into effect, giving Black men the right to vote (1870)
 - The Queensboro Bridge opened (1909)
 - Jeopardy premiered on NBC (1964)
 - President Ronald Reagan was shot in the chest outside of a hotel in the Capitol (1981)


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