He told Corax to row them toward the center of the piscina and when they reached it he handed him the torch, uncorked the bottle, and rolled up the sleeves of his tunic. How often had he seen his father do this, in the subterranean reservoir of the Claudia and the Anio Novus on the Esquiline Hill? The old man had shown him how each of the matrices had its own flavor, as distinct from one another as different vintages of wine. The Aqua Marcia was the sweetest-tasting, drawn from the three clear springs of the River Anio; the Aqua Alsietina the foulest, a gritty lakewater, fit only for irrigating gardens; the Aqua Julia, soft and tepid; and so on. A good aquarius, his father had said, should know more than just the solid laws of architecture and hydraulics—he should have a taste, a nose, a feel for water, and for the rocks and soils through which it had passed on its journey to the surface. Lives might depend on this skill.
An image of his father flashed into his mind. Killed before he was fifty by the lead he had worked with all his life, leaving Attilius, a teenager, as head of the family. There had not been much left of him by the end. Just a thin shroud of white skin stretched taut over sharp bone.
His father would have known what to do.
Holding the bottle so that its top was facedown to the water, Attilius stretched over the side and plunged it in as far as he could, then slowly turned it underwater, letting the air escape in a stream of bubbles. He recorked it and withdrew it.
Settled back in the boat, he opened the bottle again and passed it back and forth beneath his nose. He took a mouthful, gargled, and swallowed. Bitter, but drinkable, just about. He passed it to Corax, who swapped it for the torch and gulped the whole lot down in one go. He wiped his mouth with the back of his hand. “It’ll do,” he said, “if you mix it with enough wine.”
The boat bumped against a pillar and Attilius noticed the widening line between the dry and damp concrete—sharply defined, already a foot above the surface of the reservoir. She was draining away faster than the Augusta could fill her.
Panic again.Fight it.
“What’s the capacity of the piscina?”
“Two hundred and eighty quinariae.”
Attilius raised the torch toward the roof, which disappeared into the shadows about fifteen feet above them. So that meant the water was perhaps thirty-five feet deep, the reservoir two-thirds full. Suppose it now held two hundred quinariae. At Rome, they worked on the basis that one quinaria was roughly the daily requirement of two hundred people. The naval garrison at Misenum was ten thousand strong, plus, say, another ten thousand civilians.
A simple enough calculation.
They had water for two days. Assuming they could ration the flow to perhaps an hour at dawn and another at dusk. And assuming the concentration of sulfur at the bottom of the piscina was as weak as it was at the top. He tried to think. Sulfur in a natural spring was warm, and therefore rose to the surface. But sulfur when it had cooled to the same temperature as the surrounding water—what did that do? Did it disperse? Or float? Or sink?
Attilius glanced toward the northern end of the reservoir, where the Augusta emerged. “We should check the pressure.”
Corax began to row with powerful strokes, steering them expertly around the labyrinth of pillars toward the falling water. Attilius held the torch in one hand and with the other he unrolled the plans, flattening them out across his knees with his forearm.
The whole of the western end of the bay, from Neapolis to Cumae, was sulfurous—he knew that much. Green translucent lumps of sulfur were dug from the mines in the Leucogaei Hills, two miles north of the aqueduct’s mainline. Then there were the hot sulfur springs around Baiae, to which convalescents came from across the empire. There was a pool called Posidian, named after a freedman of Claudius, that was hot enough to cook meat. Even the sea at Baiae occasionally steamed with sulfur, the sick wallowing in its shallows in the hope of relief. It must be somewhere in this smoldering region—where the sibyl had her cave and the burning holes gave access to the underworld—that the Augusta had become polluted.
They had reached the aqueduct’s tunnel. Corax let the boat glide for a moment, then rowed a few deft strokes in the opposite direction, bringing them to halt precisely beside a pillar. Attilius laid aside the plans and raised the torch. It flashed on an emerald sheen of green mold, then lit the giant head of Neptune, carved in stone, from whose mouth the Augusta normally gushed in a jet-black torrent. But even in the time it had taken to row from the steps the flow had dwindled. It was scarcely more than a trickle.
Corax gave a soft whistle. “I never thought I’d live to see the Augusta dry. You were right to be worried, pretty boy.” He looked at Attilius and for the first time there was a flash of fear across his face. “So what stars were you born under, that you’ve brought this down on us?”
The engineer was finding it difficult to breathe. He pressed his hand to his nose again and moved the torch above the surface of the reservoir. The reflection of the light on the still black water suggested a fire in the depths.
It was not possible, he thought. Aqueducts did not just fail—not like this, not in a matter of hours. The matrices were walled with brick, rendered with waterproof cement, and surrounded by a concrete casing a foot and a half thick. The usual problems—structural flaws, leaks, lime deposits that narrowed the channel—all these needed months, even years to develop. It had taken the Claudia a full decade gradually to close down.
He was interrupted by a shout from the slave, Polites: “Aquarius!”
He half turned his head. He could not see the steps for the pillars, which seemed to rise like petrified oaks from some dark and foul-smelling swamp. “What is it?”
“There’s a rider in the yard, aquarius! He has a message that the aqueduct has failed!”
Corax muttered, “We can see that for ourselves, you Greek fool.”
Attilius reached for the plans again. “Which town has he come from?” He expected the slave to shout back Baiae or Cumae. Puteoli at the very worst. Neapolis would be a disaster.
But the reply was like a punch in the stomach: “Nola!”
The messenger was so rimed with dust he looked more ghost than man. And even as he told his story—of how the water had failed in Nola’s reservoir at dawn and of how the failure had been preceded by a sharp smell of sulfur that had started in the middle of the night—a fresh sound of hooves was heard in the road outside and a second horse trotted into the yard.
The rider dismounted smartly and offered a rolled papyrus. A message from the city fathers at Neapolis. The Augusta had gone down there at noon.
Attilius read it carefully, managing to keep his face expressionless. There was quite a crowd in the yard by now. Two horses, a pair of riders, surrounded by the gang of aqueduct workers who had abandoned their evening meal to listen to what was happening. The commotion was beginning to attract the attention of passersby in the street, as well as some of the local shopkeepers. “Hey, waterman!” shouted the owner of the snack bar opposite, “what’s going on?”
It would not take much, thought Attilius—merely the slightest breath of wind—for panic to take hold like a hillside fire. He could feel a fresh spark of it within himself. He called to a couple of slaves to close the gates to the yard and told Polites to see to it that the two messengers were given food and drink. “Musa, Becco—get hold of a cart and start loading it. Quicklime, puteolanum, tools—everything we might need to repair the matrix. As much as a couple of oxen can pull.”