Wanted: Europe\'s Earliest Segmental Arch Bridge

[Lusitano]

Just search "ponte romana" in google images, you should get a lot of of images of portuguese roman bridges (and spanish too).

Here are a few.

[Gaius Julius Caesar]

Thanks Lusitano

[Lusitano]

If you find any interesting bridge with a description that you need translating let me know, if its in portuguese or spanish i can help you with it

[Niedel]

Those are clear half-circles, though, no, and not segmental?
How about the Roman bridge in Salamanca? Hard to see from this pic whether they are half circles or segmental, but I'll try to dig up more:

[Eleatic Guest]

Question: What is the ratio of span to rise in a segmental arch of 140 degree? Obviously, in a 180 degree semicircular arch the ratio would be 2:1 (2 x radius : 1 x radius), but what is a general formula for converting degrees into span to rise ratio?

[Eleatic Guest]

Interim report: You will find the earliest segmental arch bridges - worldwide - here: http://de.wikipedia.org/wiki/Kategorie: ... r%C3%BCcke

They are Roman.