Walpuski's "Ordinary Form of Pencil"

While I was researching the various patent dates found on early Eagle Stop Gauge pencils, I'd mentioned that the most difficult one to pin down was Charles Walpuski's patent from June 26, 1877.  It was tough to find because patent was for a formulation of lead, rather than for the pencil itself, so it wasn't indexed where you would expect to find it. 

Walpuski's idea was a pretty neat one:  if soluable dyes are mixed in with graphite and clay, a pencil using such lead writes normally on a dry surface.  Then, if you wanted to make a copy of what you'd written, all you needed to do was lay a moist piece of paper on the manuscript, which would cause the dyes to dissolve and transfer to the moist paper, which could then be pressed onto other sheets of paper to make copies. 

What is curious about Walpuski's patent is that while his patent has absolutely nothing to do with the pencil itself, he includes a drawing of one anyway.  In the text, he states, "The accompanying drawing represents one ordinary form of pencil in which my invention has been embodied."

NOTE:  This article is now included in the print version of The Leadhead's Pencil Blog, available anywhere you buy books, or also from The Legendary Lead Company.

To order, here's the link:  Volume 1 at Legendary Lead Company