Picture from "Feuerwerks und buchsenmeisterbuch"
 

I can't understand appointment of this subject:

Is there a caption or bit of text accompanying this mysterious drawing? I would imagine from the title of the book that it would be in German, I'm sure there's a number of us on the forum who can help you with a translation.

I would love to help in translation but even if there is a text relating to this illustration (which usually is not the case) it will not be easy to read the Gothic minuscule script. Perhaps we will be lucky though if Alexander took the line drawing from a transcribed later editition.

Any comment or brainstorming on this curious object is much welcome!!!:shrug:

Best,
Michael

Alright,

Now I went thru the book (ca. 1470, Cod germ. 734, Bavarian State Library Munich), only to find my surmise confirmed: there is no caption to the illustration nor is there a reference in the (very hard to read!) text.

However I found a similar but more exact line drawing in there (first attachment) and all of a sudden the idea of a primitive caliper rule jumped to my mind (a modern version also attached).

Any comments out there?

Best,
Michael

Great shot, Miguel.
Somethingi wouldn't guess :)