Monday, March 15, 2010
A Mr. Nada Peckerwood from Flacid Lake Illinois asks...
'Dear Mr. Knowitall, last night my wife told me that I have no lead in my pencil!
Do they still put lead in pencils'?
Dear Mr. Peckerwood...Not Anymore!
The ancient Greeks, Romans, and Egyptians used small lead disks for drawing guidlines on papyrus before writing and painting with brushes and ink.
Rods of lead, silver, and zinc were also used to make light drawings, but that changed in 1564 when a huge graphite deposit was discovered in Borrowdlae England.
Using graphite to draw wasn't new. Long before Columbus, the Aztecs used graphite for much of their art. They took the graphite, and carved pointed 'marking stones' out of it. The problem was that they marked the writer's hands as much as what they were drawing or writing. Eventually that problem was solved by wrapping string around the sharpened stones, and unwrapping the string as the points wore down.
That was the first version of the modern pencil!
And speaking of the modern pencil, I bet you're wondering how the graphite gets into the wooden casing aren't you?
* First the graphite is ground up and mixed with a fine clay. The more clay that is added...The harder the lead!
* Then the mixture is forced through an 'extruder' to make a long thin rod.
* The rod is then fired at a temperature of 2200 degrees F to harden, and then treated with wax for smooth writing.
* The wood is sawed into small boards that are the length of one pencil, the width of seven pencils, and the thickness of a half a pencil.
* Seven tiny grooves are cut lengthwise. Then the lead is laid into each of the grooves, and an identical board is glued on top. Finally a machine cuts the board into seven individual pencils. A Non-Toxic paint is applied, and VOILA!!
Good question Limpy!
Mr. Knowitall grows weary...
So always remember, You can lead a horse to water-But a pencil must be lead!
(Or graphite :P)