[split] Taccola spillover thread

[Jorge_Stolfi]

I disagree. They are failed copies. I marked a relevant area with A. We can see an end of a pipe there and a water flowing out of it.

Good eye!  And there are in fact other similarities:

• The hole in the ground at the left end of the bridge in 1,2
  
• The second mountain at NE in 2,3
  
• The wavy wall(?) at the foot of the hills in 2 becomes a cliff in 3.
  

As I wrote before, my guess is that the bridge was meany to be a You are not allowed to view links. Register or Login to view. to take channeled water over an obstacle.  If so, it must have been just a "theoretical invention".  Such a siphon must be primed by filling it with water.  That would be tricky for a siphon of that size...

All the best, --stolfi

[gerrydelasel]

 If so, it must have been just a "theoretical invention".  Such a siphon must be primed by filling it with water.  That would be tricky for a siphon of that size...

You bung both ends of the pipe, fill up the pipe by pouring in water at the apex, seal over the hole in the apex, then remove the bungs.

[Koen G]

I disagree. They are failed copies.

This is not a matter of opinion, you confidently stating falsehoods as facts. I just hoped I could get away with a quick explanation, but well, here we go.


As a reminder, the MS that contains book III and IV of De ingeneis is Pal 766. This is an autograph by Taccola, made 1432–1433 and intended as a dedication to the Emperor upon his visit to Siena. It is unclear whether a separate copy was given to the Emperor.
You are not allowed to view links. Register or Login to view. give a translation for the text with the siphon bridge drawing in Book III, the one we are interested in.

Behold the bridge in back, and near it
the city, as shown on this sheet. The
water, which springs forth next to the
river and its banks, cannot pass across
without a bridge. If the bridge were
constructed flat, it would be carried
away by the impact of water. Therefore
let a bridge be built in the shape of an
arch, so that a flood of water may pass
below it and flow off swiftly. Then let
pipes be installed on the bridge. Let
the intake of the rising pipe be smaller
in length than the discharge pipe. Make
the discharge pipe greater in length by
an extra one-fourth. To learn the way of
lifting water onto the bridge, turn to the
example in the Second Book, of the
Dragon, folio 96 [II 94v]; and it appears
more clearly in the First Book, of the
Lion, fol. 69 , done by the hand of
said Ser Mariano.

Taccola frames this as a new problem, and refers to his previous books (De ingeneis I & II) for other instances where he talked about bridge syphons. He uses drawings of animals in his works as bookmarks; you can see the "Dragon" in book II here: You are not allowed to view links. Register or Login to view. . When we go to the specified folio of the Book of the Dragon, we see this image: You are not allowed to view links. Register or Login to view.

I don't want to go through every Taccola MS to find the source of the drawbridge image, but it is clear that this is again a separate engineering problem. In the text under the drawing, you can see that it says "castellum cum ponte levatorio", "castle with a drawbridge". 

This picture should clarify the relations between all images:

   

Edit: wait, the image you labelled as being from the later model book is actually from the Taccola original, isn't it? So you're saying an image from De Ingeneis II is a failed copy of the image in De Ingeneis III, while we have Taccola in III saying "yo guys I used a similar technique earlier in II, go check it out".

[Rafal]

All right, it worked a bit differently than I thought.

These images are similar as I tried to show but it was Taccola himself who produced a lot of sketches and copied a lot of details from one sketch to another. Then some other people copied his different sketches.

So I guess we don't have any known copy of the picture from Palatino766 which is the most similar to VM. Would it be right?

[Koen G]

Yup, not any known ones. As said, there are interesting possibilities for copies to exist, but those would be speculative.

[JustAnotherTheory]

So, if the VMS Q13 was indeed inspired by Pal. 766, and knowing that Taccola finished Pal. 766 in 1433, with the famous sun face illustration on the very last page, that means that the VMS was created no earlier than 1433.

On the other hand, if the VMS was inspired by a copy of Pal. 766, then the VMS was created even later than that.

This seems to give a lower bound for the creation of the VMS, unless both the aforementioned VMS and Pal. 766 illustrations share common imagery from an earlier common source, for which no evidence exists today.

Therefore, based on the evidence we have today, it is reasonable to say: the VMS was created in or after 1433.

[DG97EEB]

But Taccola was inspired by Kyeser...I think more likely the inspiration is from the latter

[JustAnotherTheory]

But Taccola was inspired by Kyeser...I think more likely the inspiration is from the latter

Sure, that's likely. But both the bridge scene and the sun face in Pal. 766 appear nowhere else (at least nowhere that actually survived). Both of these images appear in the VMS.

So, based on the evidence we currently have, I rest my case

[DG97EEB]

1433 is perfectly plausible and based on some parchment studies I read and then modelled, 1420s-1430s is the sweet spot... My guess is still that Taccola drew on older materials and it's those that influenced not the other way round... I can't make a convincing case for Voynich in Siena or the Sigismund connection despite working both hard....

[Koen G]

One nuance is that a hypothetical copy for Sigismund would have been given to the Emperor upon his visit to Siena, after which he travelled back north. These are my current thoughts on our three options:

1. Pre-1433 common source. Note that this cannot just be any book on public water infrastructure. That is to say, there are a lot of details both in contents and style that make the Taccola bridge parallel so strong. The vertical ravine, the vertical lines along the edges, the technique used to draw the undulating stream... All of this comes on top of the layout parallels. If an older common source exists, we have not seen it yet.
   
2. Copied from Taccola's work in Siena. If he had earlier sketches (which he did), we can push this a bit before 1433. In fact, it is said that work on his four books started as early as 1419. But I assume a more general accessibility of the work in university circles can be assumed from 1433 onward.
   
3. Copied from Emperor's copy. If a copy was given to the emperor, this happened in 1432-1433. I guess the timer starts ticking at that point, since anyone in the emperor's surroundings could theoretically have seen the MS or copied from it.
   

All of those are speculative, we only know for sure that:
* The work was completed in Siena in 1433 and very likely kept there.
* The work was shown to the emperor at the same time.