Hi Andi,
I like the idea but...
there would be some technical problems setting the city on fire with a fire lanz when there is a moat around the city? Also Franz Helm has been know for window dressing his books with imaginary things.
It wouldn't be such a succes making a fire lanz completly out of wood either?
I doubt it is a tar lance, those tar lances where shot by balista's and had incendiary loads inside the barrrels made of iron.
I am not saying it is not a fire lance, but it is not yet clear to me how such a weapon could be used in a situation as portrait at the manuscript of Judith and Holofernes.
It shows a city on fire and one (possible) fire lance flaming. A moat surrounds and blocks the path to the city so no direct contact can be made.
I this situation i am sure they would rather have used incendiary arrows. The depiction is in my eyes (for the moment) only to show of this "magical" weapon (propaganda maybe?) Also the whole picture is out of proportion or someone really liked bonsai trees. Not uncommon though in the (late) medieval times to draw important things out of scale.