Heliodorus\' Aethiopica

[Nathan Ross]

in the second Oration to Constantius.

Oh, hang on - I thought there was only one! Is the 'second' the one you quoted in an earlier post?

From the first oration:

"then the river Mygdonius flowed in and flooded the ground about the walls, as they say the Nile floods Egypt"

An odd detail about Egypt there... perhaps suggestive as a link back to Heliodorus? Or it could have suggested the story to Heliodorus, perhaps...

Julian's account stresses that the damns broke suddenly at a full-tide

Did it? I thought the breaking dams are only in Theodoret et al and the life of St Ephraim... Which bit have I missed?

And what would 'full tide' be in a river about 800 miles from the sea? Perhaps he means when the dams were full?

However, there is this note (first oration again):

"For who ever heard of surrounding a city with water, and from without throwing hills about it like nets, then hurling at it, like a siege-engine, a river that flowed in a steady stream and broke against its walls"

The 'siege engine' simile is much like the 'battering ram' mentioned by Theodoret, so it sounds like Julian is indeed saying here that Shapur used concentrated water pressure to collapse the walls. This would surely contradict the idea that the Persians dammed the river below the city and let it overspill its banks to form a lake? Very confusing!

I...wonder if the four month period represented how long it took for a sufficient dam of water to build up about Nisibis (or part of it) sufficient to be released and batter the walls? Shapur has his engineers utilise the waiting time to harass the walls and undermine them with rafts and barges/boats as nothing more than preparation for the release.

I did wonder some time ago (confession - I've been interested in the Nisibis siege for a while!) whether the availability of water in the Mygdonius might be a way to estimate which season the siege took place. The river flows down out of the mountains into desert, so presumably would be in spate at the time of the melting of the mountain snows - spring, perhaps? Quite what volume of water it might carry at such a time, or how long it would take to accumulate, I don't know!

However, if the water was to be concentrated and then released against the walls, Shapur would have to dam the river above the city. This would leave the riverbed dry around the walls themselves. To create a lake, on the other hand, he would build his dam below the city...

There's always the possibility that Julian is confused in his note about the 'recent' siege, and that Shapur tried two different applications of water engineering against Nisibis, first using the watery ram, as described by Theodoret, in 337 and then the artificial lake (with or without boats!) in 350. This would partly explain things, perhaps, although we'd have to wonder why Julian thought both tactics had been used during the same episode.