“Well, then, that’s how we’ll make this engine work,” he said, forcing cheerfulness into his voice.
“Yes, but I really don’t think it can be done with iron,” the metalworker replied. “Iron is too hard—and too hard to cast, honored sir. By the Sun God, I speak the truth.”
Adrian sighed and let his head drop into his hands. My back hurts, he thought; he was never, never going to get used to sitting cross-legged on cushions.
“All right,” he said. “We’ll start off by using bronze for the pistons. We want two, to begin with, six inches in bore and four feet long. But the piston rods will have to be made of iron—wrought iron.”
“Hmm-auhm,” the Islander—his name was Marzel, a plump little man with a snuff-colored turban—said.
He picked up the model Adrian had had made by standing over a toycrafter. It showed a single upright cylinder, with a piston rod coming out of its top. The rod connected to one end of a beam; the beam was pivoted in the middle, and the other end had a second rod that worked a crank, that in turn moved a wheel with paddles.
“I’ve seen wheels like this used to move grindstones,” Marzel said. “This is the same thing in reverse, isn’t it?”
Gray-Eyed Lady, thank You, Adrian thought. Finally, someone who understands what I’m talking about!
“Exactly!” he said aloud. “The steam pushes the piston, the piston pushes the beam up and down, the crank turns that into around and around, and the wheel pushes the ship—one on each side.”
“Hmmm-auhm,” Marzel mused again. “You know, honored sir, one could use this to move a grindstone, too.”
A hecatomb of oxen to you, Lady of Wisdom. Aloud: “Yes, it could—think of it as a way of transforming firewood into work, the way a man or a velipad converts food into work.”
Marzel laughed aloud. “Ah, you have a divine wit, honored sir!” He returned to the model. “So, let me see if I have grasped this. The steam goes through these valves here, at each end of the cylinder. As the piston moves, it uncovers these two rows of outlets here at the middle of the cylinder, letting the steam escape.”
At Adrian’s nod, the artificer turned back to the plans, tracing lines across the reed-paper with a finger and then referring back to the model.
“Honored sir,” he said at last, “I love this thing you have designed—so clever, you Emeralds! Yes, I love the thought of making it. But I am not sure that it can be made, in the world of real things. In the . . . how do you Emeralds say it? In the world of Pure Forms, yes, this will work as you say. But it has so many valves, so much piping, so many joints, you see. Holding water in such a thing, for say the fountains and curious metal beasts in the Garden of Curiosities in the King’s Palace, that is difficult. Holding hot steam . . . can fittings be made precisely enough? Even with the finest craftsmen? And these parts will be large.”
Adrian nodded in respect for the man’s honesty; and his courage, expressing doubts here in the palace rather than telling the royal favorite whatever he wanted to hear.
“I am certain that if any man can do it, Marzel Therdu, you can,” he said. “And I am certain that it can be done.” He spread his hands and smiled. “And my head answers for it, if it cannot, not yours.”
Marzel rose and made the gesture of respect, bowing with palms pressed together. “Perhaps . . . Perhaps we would be well advised to try first a model of this thing, this . . . hot water mover?”
“Steam engine.”
“Steam engine, then. Not a toy model, although that was useful. A working model, enough to drive a small launch, of the type rowed by ten men?”
probability of success of steam ram project has increased to 61% ±7, Center said. as always, stochastic analysis cannot fully compensate for human variability.
Adrian smiled; if that had been a human voice speaking aloud, and not a supernatural machine whispering at the back of his mind, he’d have sworn there was a rasp of exasperation in it—rather the way one of the professors of Political Theory in the Academy had spoken of the Confederacy of Vanbert’s Constitution; it should not work, but it did.