He stepped out into the sunlight with the gigantic Brand and the limping kite-boy at his heels, followed by a glower from Svandis. She wanted to listen to the end of the strange book. At the same time she resented the way her lover could turn his attention instantly to something new. Something without her.
“I brought two people to talk to you,” added Brand once they were in the open. “Steffi and a native.”
Shef turned his attention first to the native, as Brand called him, another dark-faced man of clear Arab descent: there were still many non-Jews in the town, traders caught by the unexpected closure of roads.
“You speak Arabic?” he asked.
“Of course.” A slight sneer at the question: Shef’s Arabic was no more than serviceable, far removed from the pure tongue of Cordova or Toledo.
“What is your news?”
“The Christian Emperor, your enemy and the enemy of my master the Caliph, has destroyed many walls and forts this summer. He has killed many of the faithful too, all along the sea-coast they once controlled. Do you wish to know how he did it?”
“We will pay gold for it,” Shef replied.
“I would tell you anyway, as a service against the Nazarenes. He has a machine. Only one machine, and it is many times bigger than anything you have here. He uses it for only one thing, and that is to hurl great boulders on to his enemy’s gates. Some say that it needs flat ground, that it can shoot only very slowly.”
“Have you ever seen it?”
“No, but I have spoken with men who escaped with their lives when strongholds were taken.”
Bit by bit Shef drew from the Arab what little accurate information he could provide, and began to realize the use of the counterweight. Absently he dismissed the man, thinking already of the problems of a pivot, of retention and release: above all, the central problem of all the traction engines, of how to control range. It depended on weight. There must be some way to tell, if you knew how much was in the counterweight and how much in the launching-sling, what you needed to add or to take out in order to throw a set distance. But a three-element calculation was beyond Shef, or any other man in his realm. Even working out how many water-barrels you needed, or what share of loot went to each ship or each man, was a trial-and-error business with the Northern counting-system. Shef wished in frustration that he too, like Bruno, had in his service an arithmeticus. Even someone who knew what arithmetic might be. As he pounded a fist into his palm he became aware that Steffi was standing on one foot, eying him nervously from his usual wide angle.
“Why did Brand send you here?”
“I was thinking. About the flares we used from the kites. And that time I jumped off the cliff, you remember? I was thinking, how would it be, at night like, if we had some flares ready to light, and threw them from a pull-thrower? We could put some cloth on so they’d open out, see, and come down slowly, with a hole in, like we’ve learned how to do…”
After a few further moments explanation Shef sent Steffi off to find a gang and practice attaching the cloth.
“Don’t light anything, mind,” he warned him. “Just figure out how they have to be rigged to open properly. Go easy with the saltpeter crystals, it’ll take time to make more.”
As the squint-eyed ex-slave went off, Shef’s mind went back to the counterweight machine no doubt already approaching. His eye fell on the still-bandaged Tolman. The lad had been silent and downcast ever since he came round from his long unconsciousness, not surprising with his two comrades dead. Could another boy be used? No, there was no doubt that Tolman was the most experienced flyer, the most likely to succeed. Yet he would have to be persuaded.
Shef’s face took on the reasonable and friendly air that his closest associates had come to dread, the expression that showed he was about to use someone.
“Well, Tolman,” he began. “Like to try a flight over nice soft water this time? Get your nerve back before it goes, eh?”