I sat down and stared at Meekal. I picked up a fly whisk and waved it vaguely about my head. Everyone else was still clutching the ground, as still as in death.
‘Then, if you’ll pardon me for saying,’ I sneered, still in Syriac, ‘you’re a right barbarian. We aren’t talking here about a recipe for fish sauce. I need complete freedom to research as I see fit. Do you want the Caliph to stand up and cheer when I set those kettles off? Or do you want to offer him an unusually vigorous steam bath?’
‘I have just finished a meeting with the Caliph,’ came the response in a voice that really did remind me of one of my kettles. ‘He was accosted on his return to the palace by the Director of the observatory you had just plundered. His Majestic Holiness was not pleased.’
I got up and laughed. I walked close to the edge of the roof and rapped hard with my stick on a bronze adjustment bar.
‘So that’s how it is,’ I cried in a loud voice. The breeze had dropped down again, and my voice was flat but clear. I made sure to keep in Syriac. ‘When the Commander of the Faithful is away, you’re top dog. When he’s back, you answer to his finance clerks. And to think you betrayed your family, your country, your religion for this. I could have got you made Exarch of Italy. Why, you’d have had more authority as Prefect of Cartenna!’
Meekal glanced down at the carpet of grovelling bodies. ‘Get off this roof – all of you!’ he snarled softly. He waited until everyone had darted through the hatchway in the centre of the roof that led down to the access ramps. He kicked the hatch closed and came back to me. I was back in my chair, and was pretending to inspect the handle of my fly whisk. He stood over me. His black robes heaved in time with his breathing. ‘If you cannot do so in private, I do suggest, for your own good, that you show some respect in public.’
‘Fuck you, Michael!’ I answered in Greek. I looked up at the cloudless sky. My left leg was hurting, and I could feel the need for a piss coming on.
‘Is there one reason,’ he asked slowly and with much effort, ‘why I shouldn’t have these things collected at once and taken back to where they belong?’
As I was wondering how he’d react to my standing up and pissing close to his feet, I heard the first scrape of the water screw. It was over on the far side of the tower. But, without the insulation of walls and glazed windows, the laboured, squealing, grating sound was unpleasant on the ear. I clutched hold of a brass lever and pulled myself up. I held out my arm for Meekal to take. Together, we made our way across the roof to where the covered water tank was placed. For the moment, the noise came from below, as water was pushed up the rotating lower screw to the tank within the tower. Then, with a more continuous and still louder screech of bronze pipe within bronze hoops, the upper screw began to rotate. At first, it was just a shuddering movement of weather-corroded metal. Then, with a loud splutter, the first bright splash of water jumped on to the collection pan and was channelled into the lead tank. It was like watching a giant, if sluggish, ejaculation as the tank was slowly filled. Far below – perhaps right on the ground, perhaps within the tower itself – there came the higher sound of a whip and a suppressed cry. Someone laughed unpleasantly, and there was another crack of the whip.
‘You know,’ I said, speaking as best I could above the noise, ‘I’ve been wondering ever since I came here if some arrangement of gears wouldn’t cut out the need for a break into the pipe.’ I waited for the puzzled look on Meekal’s face to pass. I waited in vain. I shrugged and let him help me on to the low stool he’d carried across with us. Water was now running back down the pipe, and this was lubricating its movement within the hoops. The noise had changed to a dull, continuous grating of metal on metal. ‘It’s about seventy feet from here to the ground. There’s no reason why a single pipe of that length can’t be made. Each of the two existing lengths was cast in sections, then welded together. The two sections themselves could easily be joined. The limitation is that the highest rotation speed isn’t enough to push water the whole distance. That’s why the engineers broke the course with a supplemental tank. But if the rotation speed could be increased without limit, there might be no limit to how far water could be raised. That’s why I thought of gears.
‘Since yesterday, though, I’ve been thinking further. I used steam in our demonstration as a substitute for the real thing. But suppose you could match a steam kettle to the sort of wheel you see on a water mill. That, plus the gears, would give enormous force to any rotation. You’d be turning heat into motion. Has it ever struck you that all human might so far has been based on the power of human or animal muscles?’ I ignored the lack of response. I was speaking now more for myself than for Meekal. If he’d gone and thrown himself off the roof, I might have got up for a dance of joy. Or I might have carried on with the lecture.
‘Even when there is no limit to the quantity of muscle power, there are limits to its effective use. Yet heat can be generated wherever there are adequate supplies of fuel, and can be converted into both intense and rapid motion. Give me funding and a team of engineers and metal workers, and I’ll give you a machine that will raise water seventy feet – and have it spurting ten feet beyond that. Indeed, once the basic point is realised, of the conversion of heat to motion, I can imagine ships that sail regardless of winds and tide, and vehicles that can travel on the roads day after day at the speed of a galloping horse.’
‘You’ve been at that shitty opium again,’ Meekal sneered.
I smiled and sat up. I took off my visor and waved it at him. ‘Bearing in mind what I have already achieved,’ I asked, ‘must I make out the same case, in each and every other instance, for the benefits of understanding and controlling the world about us? Can you not at least see that the first civilisation to bow before the power of natural reason will conquer the world? Is not the weapon I am about to give you a feeble thing compared with what might one day be? Are not your own victories in the East as much an effect of chain mail and swords as of religious enthusiasm?’
Meekal gave one of his contemptuous laughs. He held out a hand to take my arm and led me over to the exit hatch from the roof. I stopped by one of the larger instruments. Its calibration marks told me it was of Alexandrian workmanship – possibly from before the Roman conquest of Egypt. For something of its age, it was in good shape. A pity, though, that seven hundred years hadn’t rendered it as obsolete as the numerals that had to be learned before it could be made to work. I pulled free of Meekal’s grip and carefully sat myself on the warmed lead within the shadow of the instrument.
‘Do you remember that story told of Tiberius – the Emperor who succeeded Augustus in ancient times, not the one a hundred years back who came before the unfortunate Maurice?’ Still nothing from Meekal. I got slowly up and looked over the rooftops of Damascus. The breeze was coming up again. ‘He was approached one day by a craftsman who said he’d made a new sort of glass cup. As the Emperor reached out to take the cup, the craftsman let it fall from his grasp. Tiberius stood back to avoid the smashing of glass on the floor of his palace. Instead of shattering, though, the cup bounced on the marble. The craftsman took it up and produced a little hammer, so he could knock out the slight dent of the impact. Impressed, Tiberius asked if anyone else knew how to make such glass. “No,” came the answer. It was a secret known only to one man. Was he rewarded with a kiss of joy and a soft loan to build a bigger workshop? No, he had his head cut off. Let the secret of unbreakable glass be common knowledge, said Caesar, and no one would ever commission cups of gold and silver. After a while, no one would even buy new glass cups. The death of one man, he said, was essential, if thousands were not to lose their livelihoods.