He was due to take the stand today.

‘We have made eight reservoirs.’

‘Then you have made eight mistakes!’

Gunson gripped the polished walnut of the witness box, stung into speechlessness.

John Webster, now sitting as the coroner of inquests, one of the many hats the man wore, was implying – nay, stating – that the principles upon which all the reservoirs surrounding Sheffield had been built were unsound. That any one of Gunson’s creations might fail as Dale Dyke had.

Perronet Thompson, the barrister brought in to act for the Sheffield Waterworks Company, raised one finger and spoke mildly into the echoing silence that followed.

‘Sir, might I suggest that these are observations which ought not to be made in the presence of the jury?’

Gunson looked across at the impassive faces of the jurymen. He had been engaging so intensely with John Webster that he had entirely forgotten he was in a courtroom packed to the rafters with townspeople. The largest courtroom in the town hall had been allocated to the inquest. It was a room designed to endanger fear in the accused, not that, he reassured himself, he was being held on trial. The dock beside the box he stood in was empty. However, the seating allocated to the jury and the bench at which the coroner and his clerks sat were elevated so Gunson was required to look up to address Webster, like a supplicant. And members of the public crowded the upper galleries that ran along both sides of the room, as well as standing in every available space not taken up by bulky benches and chairs and tables. The overall effect was to make him feel claustrophobic, as if he stood at the bottom of a well with everybody peering down at him.

To make matters worse, and despite the room’s high ceiling, the air was stuffy with bodily odours. He would give anything for a breath of town air, a whiff of chimney soot and sulphur coming in on a light breeze or the heavy scent of hops from the brewery to tickle his nostrils.

‘Why should I not speak freely?’ said Webster. He poked his head forward like a man sniffing blood. ‘I am merely asking this engineer to speak like a rational man. If there was a fracture in a pipe…’

‘We do not know what caused the catastrophe,’ said Gunson quietly.

‘…how could you be alerted to it? There is no access to the pipes once they are laid and buried and all the evidence is certainly destroyed now. Your work at Dale Dyke not being perfect…’

‘I thought the embankment perfect up to the time of its giving way.’

‘…have you not reason to think that your Agden reservoir that is now under construction…’ Webster broke off. ‘I’m sorry, what did you say? About the perfection of the dam?’

Gunson cursed himself.

The company’s barrister finally met his pleading eyes, but merely raised his eyebrows under his shock of thick white hair. Gunson wondered why Perronet let his hair grow so long at his age and why he was not defending him more robustly. But when he opened his mouth to reply to Webster, intending to explain himself more fully, Perronet gave an almost imperceptible shake of his head. Webster would not wait long for a reply, and he didn’t.