Right at the start of (1970) “Brunelleschi: Studies of His Technology and Inventions” (pp. xi-xiii), Frank Prager summarizes Gustina Scaglia’s research into how Brunelleschi’s ideas for machines spread. They posit a key missing manuscript (dubbed “The Machinery Complex“): but their discussion is fairly specialised, and so it is quite tricky to follow. Here’s my attempt at representing the argument – green boxes represent manuscripts that still exist, red boxes represent lost works, while blue boxes I’m not sure about:-
Which is to say: while all the early Renaissance machine ideas ultimately stemmed from Brunelleschi, later machine authors (such as Francesco di Giorgio) relied not just on Taccola’s De Ingeneis but also on the missing “Machinery Complex” manuscript. However, nobody knows who wrote this or what subsequently happened to it – we can perceive it only by its shadow, hear it only by its echo in other manuscript and copyworks.
I think the reason that Prager & Scaglia’s text is a little confused is that, because the Machinery Complex ms has disappeared, they can’t quite make up their minds how much it influenced subsequent writers on machines such as Bartolomeo Neroni, Antonio da San Gallo, Oreste Biringuccio, and Pietro Cataneo. It’s an open question.
But here’s where it becomes a cipher history issue. As I mentioned here a few days ago, the text around what Prager and Scaglia call “the secret hoist” is written in an simple substitution cipher (one letter back in the alphabet) – but because this would have been seen as a childishly simple cipher by 1450, I infer that this ciphertext was not only present in Lorenzo Ghiberti’s original (but now lost) Zibaldone, but also that he probably wrote it in the 1430s or, at a push, the 1440s.
There’s also a cipher / codicological element to this argument, based on the observation that the pages containing the secret hoist are separated by several pages in the later copy of the Zibaldone (by Lorenzo Ghiberti’s grandson Buonaccorso Ghiberti). My suggestion is that Buonaccorso received the folios out of order, but copied them in precisely the same order – had he deciphered the two “secret hoist” pages and grasped that they were referring to the same thing, my guess is that he would have put them back into their correct order.
All in all, then, my inference here is that the simple cipher on the secret hoist was in place in Lorenzo Ghiberti’s original Zibaldone, and that even though Ghiberti himself died in 1455, we can probably date his missing Zibaldone to around the 1430s purely from the simplistic cipher used in it. (Of course, scientists hate this kind of art history “probabilistic proof”, but that’s how history works.)
So far, so marginal: but here’s my “aha” moment of the day, that propels all this into a different league.
One of the things I flagged in my book “The Curse of the Voynich” (pp.141-142) was that Antonio Averlino (Filarete) may have based his (now-lost) book of Engines (“when the time comes, I will mention all these engines“, etc) on this (also now-lost) Machinery Complex – and that some of these engines may well be visually enciphered in the Voynich Manuscript’s Herbal-B pages.
However, on further reflection, it seems I really didn’t go far enough: because Antonio Averlino almost certainly started his career in Lorenzo Ghiberti’s workshops, before suddenly leaving Florence in 1433 for Rome. If we were looking for someone to carry Brunelleschi’s ideas (via Ghiberti’s Zibaldone, probably written in the 1430s) into the world, we could surely do no better than look to Antonio Averlino – I strongly suspect that he was the intermediary.
So, the question then becomes: was Antonio Averlino the author of the Machinery Complex? I strongly suspect that he was, and that the Machinery Complex will turn out to be a synthesis and development of Ghiberti’s ideas as seen from Averlino’s edgy and ambitious perspective – that is to say, that the Machinery Complex will turn out to be Averlino’s missing book of Engines. And if it also turns out (as I suspect it will) to be the case that this Machinery Complex lies visually enciphered in the Voynich Manuscript’s Herbal-B pages, what an extraordinary story that would be…
PS: as a footnote for further study, the only other paper I have found on the Machinery Complex was on The Art of Invention bibliography webpage: Gustina Scaglia’s (1988) “Drawings of forts and engines by Lorenzo Donati, Giovanbattista Alberti, Sallustio Peruzzi, The Machine Complex Artist, and Oreste Biringuccio“, Architectura, II, pp. 169-97. Definitely a paper to go through to see what conclusions Scaglia had reached about this intriguing missing document. But please let me know if you find any other references!