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-   -   How Green Is Your Pencil? (http://cellar.org/showthread.php?t=24187)

footfootfoot 12-17-2010 01:32 PM

How Green Is Your Pencil?
 
Nifty?

http://www.re-nest.com/uimages/re-ne...perpencil2.jpg
Quote:

The P&P Office Waste Paper Professor turns paper into pencils when you add the lead, glue, and power. It also includes a pencil sharpener on the side. Designed by Chinese natives Chengzhu Ruan, Yuanyuan Liu, Xinwei Yuan and Chao Chen, this innovation has gained a lot of intrigue. What do you think?
http://www.re-nest.com/re-nest/hot-o...pencils-134924

By lead they mean graphite, but then China, who knows?

glatt 12-17-2010 01:38 PM

Why do they call it pencil "lead" anyway? I find it hard to believe that lead was ever used. Lead has been used in paint to make paint whiter, but I don't think lead makes a dark pigment at all. You would want a dark color coming from a pencil.

footfootfoot 12-17-2010 01:48 PM

They did use lead and other soft metals at one time. I did some silver and gold point in school.
http://en.wikipedia.org/wiki/Silverpoint

xoxoxoBruce 12-17-2010 03:02 PM

Quote:

Originally Posted by glatt (Post 700603)
Why do they call it pencil "lead" anyway? I find it hard to believe that lead was ever used. Lead has been used in paint to make paint whiter, but I don't think lead makes a dark pigment at all. You would want a dark color coming from a pencil.

You obviously haven't handled much lead, or lead oxide. Find an old fishing sinker or some shotgun shot, and you can write the great American novel.

HungLikeJesus 12-18-2010 10:05 AM

And why is "lead" spelled just like "lead"?

Griff 12-18-2010 10:13 AM

... because lead makes a nice leader.

glatt 12-18-2010 10:17 AM

Quote:

Originally Posted by xoxoxoBruce (Post 700610)
You obviously haven't handled much lead, or lead oxide. Find an old fishing sinker or some shotgun shot, and you can write the great American novel.

Interesting. This goes against my experience. I have handled plenty of lead, and it was all kind of dirty, but shiny just underneath.

footfootfoot 12-18-2010 12:16 PM

And the shininess oxides rapidly, so it would make the line dark rather quickly. See the wiki link for 'splanation.

Griff 12-18-2010 02:34 PM

Having recently removed the lead from my pencil, I'm feeling greener already.

xoxoxoBruce 12-18-2010 02:58 PM

Quote:

Originally Posted by glatt (Post 700738)
Interesting. This goes against my experience. I have handled plenty of lead, and it was all kind of dirty, but shiny just underneath.

Quote:

Originally Posted by footfootfoot (Post 700751)
And the shininess oxides rapidly, so it would make the line dark rather quickly. See the wiki link for 'splanation.

Take a pot of melted lead, the surface is all gray and crappy looking from the oxide. Now skim that oxide with a ladle, ooh, it's all shiny looking. But by the time you get the ladle all the way across the pot, and dump the oxide, the surface has gone gray again. It happens less quickly to solid lead, of course, but it won't be shiny very long.

Now if you write with lead oxide, the line won't be black like graphite, but gray. Strangely, if you write with it in Canada it won't be gray, but grey. :haha:

glatt 12-21-2010 11:46 AM

So with all this talk, I figured I'd look into the pencil and lead relationship.

According to wikipedia (I know, I know) graphite has been used in pencils since somewhere in the 1500's and 1600's.

Wikipedia claims that actual lead was never used in pencils, but there is no citation for that.

There is a mention of lead styluses being used on papyrus, but there is also no citation given for that.

But the interesting thing is that Wikipedia says that when graphite was discovered in the 1500's, the primitive chemists back then thought it was a form of lead. So they called graphite "lead." That's why pencils are said to have lead. It's simple ignorance passed down over the centuries.

footfootfoot 12-21-2010 01:00 PM

Quote:

Originally Posted by glatt (Post 701196)
It's simple ignorance passed down over the centuries.

Well, it's not the first time that has happened.;)

HungLikeJesus 12-21-2010 01:17 PM

Just ask the Indians.

Sundae 12-21-2010 01:21 PM

Quote:

Originally Posted by HungLikeJesus (Post 701220)
Just ask the Indians.

I ask them whether they'll deliver curry within a three mile radius.
I usually like the answer.

xoxoxoBruce 12-22-2010 12:53 AM

Not those Indians, but you're proving his point.


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