Original sources of image on p.26 and proof on p.62 of the PD

[El Sjaako]

I found them! I actually found them a while a go, but never got around to telling anyone. I figured I'd post it like this so it could be easily saved/shared/reposted without losing context:



It kind of exited me to find out Donald Knuth had actually commented on this (He's math-famous, mostly for writing The Art of Computer Programming and inventing/writing Tex and Metafont).

I thought I also scanned the question and more context for the rock engravings, but I can't find them. If anyone is really interested and unable to access a library with Scientific American archives I would be willing to lend the book again and scan more, although it might be better to have someone with access to a color scanner do it.

[Triple Zero]

Wow, great find, Sjaako!

[Triple Zero]

BTW these images are not in the scans of the 3rd edition we have.

[El Sjaako]

Yeah, August 1969 is just shortly before the PD 4th edition was published, so that makes sense.