Jingo

up a plate of small cakes. “I calculate that one should get a range of almost half a mile, if one detaches the endless belt from the driving wheels and uses the oxen to wind the windlass.”
    “Really?” said Vetinari, taking in the carefully numbered parts. “And it could be built?”
    “What? Oh, yes. Macaroon? In theory.”
    “In theory?”
    “No one would ever actually do it. Raining unquenchable fire down upon fellow humans? Hah!” Leonard sprayed macaroon crumbs. “You’d never find an artisan to build it, or a soldier who would pull the lever…That’s part 3(b) on the plan, just here, look…”
    “Ah, yes,” said Vetinari. “Anyway,” he added, “I imagine these huge power arms here couldn’t possibly be operated without them breaking…”
    “Seasoned ash and yew, laminated and held together by special steel bolts,” said Leonard promptly. “I made a few calculations, just there below the sketch of light on a raindrop. As an intellectual exercise, obviously.”
    Vetinari ran his eye along several lines of Leonard’s spidery mirror-writing.
    “Oh, yes,” he said glumly. He put the paper aside.
    “Have I told you that the Klatchian situation is intensely political? Prince Cadram is trying to do a great deal very fast. He needs to consolidate his position. He is depending on support that is somewhat volatile. There are many plotting against him, I understand.”
    “Really? Well, this is the sort of thing people do,” said Leonard. “Incidentally, I’ve recently been examining cobwebs and, I know this will interest you, their strength in relation to their weight is much greater even than our best steel wire. Isn’t that fascinating?”
    “What kind of weapon do you intend to make out of them?” said the Patrician.
    “Sorry?”
    “Oh, nothing. I was just thinking aloud.”
    “And you haven’t touched your tea,” said Leonard.
    Vetinari looked around the room. It was full of… things . Tubes and odd paper kites and things that looked like the skeletons of ancient beasts. One of Leonard’s saving graces, in a very real sense from Vetinari’s point of view, was his strange attention span. It wasn’t that he soon got bored with things. He didn’t seem to get bored with anything . But since he was interested in everything in the universe all the time the end result tended to be that an experimental device for disemboweling people at a distance then became a string-weaving machine and ended up as an instrument for ascertaining the specific gravity of cheese.
    He was as easily distracted as a kitten. All that business with the flying machine, for example. Giant bat wings hung from the ceiling even now. The Patrician had been more than happy to let him waste his time on that idea, because it was obvious to anyone that no human being would ever be able to flap the wings hard enough.
    He needn’t have worried. Leonard was his own distraction. He had ended up spending ages designing a special tray so that people could eat their meals in the air.
    A truly innocent man. And yet always, always, some little part of him would sketch these wretchedly beguiling engines, with their clouds of smoke and carefully numbered engineering diagrams…
    “What’s this?” Vetinari said, pointing to yet another doodle. It showed a man holding a large metal sphere.
    “That? Oh, something of a toy, really. Makes use of the strange properties of some otherwise quite useless metals. They don’t like being squeezed . So they go bang. With extreme alacrity.”
    “Another weapon…”
    “Certainly not, my lord! It would be no possible use as a weapon! I did think it might have a place in the mining industries, though.”
    “Really…”
    “For when they need to move mountains out of the way.”
    “Tell me,” Vetinari said, putting this paper aside as well, “you don’t have any relatives in Klatch, do you?”
    “I don’t believe so. My family lived in Quirm for generations.”
    “Oh. Good. But…very clever people in Klatch, are they?”
    “Oh, in many disciplines they practically wrote the scroll. Fine metalwork, for example.”
    “Metalwork…” The Patrician sighed.
    “And alchemy, of course. Affir Al-chema’s Principia Explosia has been the seminal work for more than a hundred years.”
    “Alchemy,” said the Patrician, glumly. “Sulfur and so forth…”
    “Yes, indeed.”
    “But the way you put it, these major achievements were some considerable time ago…” Lord Vetinari