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."
I thought it was strange that this pencil would look so much like the one pictured in Walpuski's patent and have a patent date just one day earlier, so I decided to throw in a bid and bring it home. The pencil has a wood barrel painted with gold paint and it is remarkably well preserved:
And on the opposite side of the barrel, the patent information:
So it is June 26 -- this is Walpuski's "ordinary form of pencil" after all!
Walpuski's patent was assigned to Joseph Reckendorfer, as were a host of other patents, all of which had one thing in common: the Eagle Pencil Company. A couple of Walpuski's other early patents were also assigned to Reckendorfer, but his last patent, from 1885, has no assignment on it (by that time, Eagle patents were being assigned directly to the Eagle Pencil Company).
There aren't any markings on this "Sun Pocket Pencil" to indicate that it was made by Eagle, which would be unusual if in fact it were an Eagle product. For now, I'm just going to have to index this under "Sun."
But I won't index it under "ordinary."