The Collation

Research and Exploration at the Folger

“What manner o’ thing is your crocodile?”: September 2014

What manner of thing might this be?

September crocodile

As always, leave your guesses and questions in the comments below, and come back later in the week for the reveal!

Update (8 September): The reveal is now up:


  • It is, so far as I can make out from the reproduction, some sort of astrological bookplate, and the astrology bit may identify the owner of the book, but that last bit is just a guess.

  • at first two keyworks came to my mind : volvelle & cypher .

    and then — thanks to google search (volvelle cypher) , whitney anne trettien’s blog (, and a final search in LUNA (della porta) — I found the crocodile.

    it is the inner disc of a (de)ciphering volvelle, the other part appears on the next page (73) of the book :

    De furtiuis literarum notis vulgo. de ziferis libri IIII. Ioan. Baptista Porta Neapolitano autore. [1563, i.e. 1591]
    Source Call Number:
    STC 20118a

    • Nicely done! It is indeed the inner disc of a volvelle that would be used to create ciphers, and it is indeed from della Porta’s De furtivis literatrum notis. It doesn’t actually belong to the volvelle printed on page 73, but you’re super close and you’ve got not only the gist of the crocodile but nearly all of the identifying traits, too. (If we’re going to be fussy, I’ll point out that it’s a different state than the one listed above (it’s STC 20118, not 20118a) but that is really being very fussy on my part.)

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