Tuesday, April 18, 2006

Roman builder ... whoops

This story has always made me laugh, and shows that problems with builders are not a modern phenomenon. Nor are problems with large public projects.

A Roman inscription (CIL VIII 2728; found at Lambaesis, now at Bejaia) tells of difficulties connecting the water supply at Saldae in Mauretania Caesariensis, Algeria.

In the second century AD the Toudja Aqueduct was built to feed the fountains and many public baths of this Augustan colony. Most of the aqueduct channel was raised on arches above the ground, but some of it had to run through a 428 m long tunnel cut into a hill.

A Roman engineer had a bright idea - if they dug the tunnel from both ends simultaneously, it would speed up work. Unfortunately, the plan did not work because after four years of digging, the two tunnels failed to meet up. The inscription on a cippae tells us that in AD 150 the governor of Mauritania had to ask Marcus Valerius Etruscus, Legate of the Third Legion in Numidia, to "send back" Nonius Datus, an engineer (recently) retired from the Legion.

Nonius succeeded in resolving the problem by building a transverse channel linking the two tunnels, and Saldae's water supply was connected. Nonius has also left us his own account of the story, preserved in a second inscription on the cippea (CIL VIII 18122), where he blames the contractors, not himself as engineer, for the mess.

Nonius is often credited with 'solving' the problem of two tunnels in AD 152, but if you read the inscription, he also seems to have instigated the scheme in AD 137.

This is the sort of anecdote that makes the Romans more approachable, and would not have been known had the inscriptions not been preserved. The little on altar on which they are carved is decorated with carved figures labelled: Patientia, Virtus and Spes (Hope).

Article about the inscriptions:
J.-P. Laporte, Notes sur l’aqueduc de Saldae (Bougie), L’Africa Romana, 11, 1996, p. 711-762


Torben Retboll said...

I like this story. It is entertaining and instructive at the same time.

I want to provide a reference to a recent study of this case:

Serafina Cuomo, "A Roman engineer's tales," Journal of Roman Studies, vol. 101 (2011) pp. 143-165.

Torben Retboll

Thewkeanos said...


Considered by Herodotus as the world's Eighth Wonder, this famous tunnel, was constructed by Efpalinos from Megara, an hydraulics engineer, in the sixth century BC with primitive tools and without measuring instruments.
In fact the tunnel was an aqueduct, bringing water from the spring «Hagiades» (mentioned by Herodotus as the «Big Spring»), where today the small church of Aghios Ioannis (St.John) is located, to Pythagorio which at that time was the capital of Samos. It was done in a way that it could not be detectable by raiders, who could easily, destroy it and deprive the city of the most basic resources.

The most significant feature of the construction is that the workers started working from both sides of the mountain Kastri and achieved to meet at the middle, with a tiny deviation.
The intellectual feat of determining the direction of tunneling was equally impressive.
How did Samians do this? No one knows for sure, because no written records exist. When the tunnel was dug, the Greeks had no magnetic compass, no surveying instruments, no topographic maps, nor even much written mathematics at their disposal.

1036m long, with dimensions of 1,80m X 1,80m, the tunnel goes through the mountain Kastron, at an axis North/West-South/East, 170m below the top of the mountain and 55m above the sea level. In its inner part, at a depth of 2-9 m, it is situated the channel carrying the water to the city, through clay tubes.

The Efpalinos aqueduct was used for about a thousand years, as proved from archaeological findings. In 1853 the French archaeologist Victor Guerin began searching for it. He was able to locate the spring and the beginning of the aqueduct but did not discover the tunnel. For the next 30 years people continued to look for it and it wasn't until in 1882 when a monk revealed where the tunnel was. However, due to the difficulty of cleaning the tunnel, it was abandoned and it wasn't until 90 years later in 1971 that the tunnel was finally cleaned and cleared by the German Archaeological Institute of Athens.

Interior of tunnel South entrance of the tunnel
Today the tunnel is exclusively a tourist attraction and you can walk the first 300m from the south entrance. It’s also a wonderful way to enjoy natural coolness on hot days.


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