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Machine Pencil

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by

will lee

on 25 September 2013

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Transcript of Machine Pencil

MECHANICAL PENCIL
Mechanical Pencil
The better pencil or wo
The mechanical pencil or propelling pencil were first made in the 18th century but many designs were made in the 19th and 20th century.
The mechanical pencil is shape like a LONG stick with a point where the lead stick out.Its the first idea of the mechanical pencil.

MECHANICAL PENCIL Lead
First, lead is a naturally occurring compound that is contained in many different raw materials used in many industries to produce many consumer products. Exposure to high levels of lead through various means can have damaging health impacts.
HISTORY OF THE mechanical pencil

Conrad Gesner described a lead holder pencil in 1565, but the lead had to be manually adjusted to sharpen it.
The earliest extant example of a mechanical pencil was found aboard the wreckage of HMS Pandora, which sank in 1791.
Goods and bads
The mechanical pencil save trees.
The mechanical pencil is made of polystyrene which has to downsides first it has to take a little bit of petroleum to make and second petroleum is not easy to get rid of.
Its also less dangerous cause the plastic in the mechanical pencil is softer than wood. So if you play around with pencils than get this one.
The biggest virture of a wooden pencil is that its not made out of plastic.So that means it takes less energy to produce the raw pencil material.
Over time the wooden pencil will eventually become a pile of shaving that can hypothetically be composted.
For people that don't know how to use a mechanical pencil ......
And credit
Copy write is bad.
Random video
http://www.slate.com/articles/health_and_science/the_green_lantern/2008/09/ecopencils.html
http://en.wikipedia.org/wiki/Mechanical_pencil
Mechanical Pencil facts
There is no risk of lead poisoning if you stab yourself with a pencil because it contains no lead just a mixture of clay and graphite. Still, pencil wounds carry a risk of infection for the stabee , lawsuits for stabbers.
Two British men, Sampson Mordan and John Isaac Hawkins, obtained the first patent for a mechanical pencil with refillable lead in 1822.


The modern mechanical pencil most resembles the models being developed in Japan and the United States beginning around 1915.
http://www.ehow.com/facts_7174544_mechanical-pencils.html
Some mechanical pencils are disposable; when the lead is gone, the rest of the pencil is thrown away.
http://www.pencils.com/blog/lead-in-pencils/
In the United States the governing body on this issue is the Consumer Product Safety Commission or CPSC. Current CPSC lead content standards dictate that lead used in paints or lacquers used on consumer goods must not exceed 90 PPM.
As a result of increased concern for the safety of different consumer products such as toys or art products from China, we often receive inquiries regarding the potential for exposure to lead in pencils. The only relevant concern regarding potential sources of lead in pencils is in the lacquer or paint used to finish the pencil.
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