C.H.Gordon was a professional philologist, and worked as a cryptographer during WWII. “Riddles in history” exemplifies the old saw about “all problems looking like nails to a man with a hammer.”
Gordon begins with a very interesting account of several important inscriptions that were initially rejected as fakes by Victorian era experts, but later verified by other evidence, mostly the discovery of other texts that show that the perceived errors in the supposed forgeries were not errors at all. For example, a text might appear to have grammatical errors which are later discovered to be repeated in other authentic texts and not errors but regional variations or dialect. He then explains that several inscriptions which have been rejected as dubious or even forgeries can be verified by later discoveries too — in this case by the uncovering of crypts and ciphers encoded in the texts themselves.
I was initially very interested to see what he came up with, but as I read on I realized he was attempting to “rehabilitate” some very widely rejected inscriptions and texts: in this case the Kensington Runestone, The Spirit Pond runestones, the “lost” Paraiba text, and the Vinland Map. Gordon finds hidden codes that make sense of the inscriptions, because, he reasons, a forger would never think to encode secret messages in them, especially not messages that make sense only in light of more recent archeology. Unfortunately it becomes evident very quickly that Gordon is doing extreme logical and philological gymnastics to make the codes “work”, and to find them at all.
For example, he examines the block of text in the upper left hand corner of the Vinland map and notices that if you count the words in each of the seven lines, you can then mark the letter that many characters from either end of the line to derive two “hidden” jumbles of letters, which are anagrams for a name that appears in the text, and a Latin phrase. The phrase could be interpreted as an expression of faith, and this fits with the much more ancient practice of embedding such phrases in other inscriptions… “could, might, can, probably” are his favorite words, it seems. By the time I got to his “conclusions,” I realized he was almost, but not quite, in full Von Däniken mode. Lookee here, this Aztec relief sort of looks like he’s wearing a phylactery, and the Paraiba text is Phoenician (with a hidden Jewish message) … so … Jews in Central America! This other Aztec figure has a beard! European contact! And that hat looks like a boat, and there is a bird in the picture, just like the story of Noah’s Ark! He reaches and reaches further, getting further out into crankdom as he goes.
As an example of a serious, and well-meaning effort to support the idea that pre-Columbian contacts between the old and new world were more common that supposed, it’s a curious read. There are some interesting maps, figures, and nice full-color plates of models of various ancient ships. The bits on cryptography are interesting and explained so that a layman can understand them. But the problem, I think, is that Gordon is so convinced that these inscriptions are authentic, that he goes looking for evidence until he creates it himself. The human mind is excellent at finding patterns, as we know; even patterns that don’t actually exist.
Now just because Gordon is almost certainly wrong does not mean you can’t get something out of this for RPGs. He gives some neat examples of acrostic and telestic cryptography that you might place in inscriptions in your dungeons, and the idea of pre-Columbian contact between the old and new worlds is a very common fantasy trope.