The Science of Discworld II

Mistress Weatherwax! I wish you’d stop doing this!’
    â€˜See?’ said Granny. ‘You ain’t havin’ another two!’
    â€˜No, no, I’ve just come up to deliver this for you …’
    Shawn waved quite a thick wad of paper.
    â€˜What is it?’
    â€˜â€™Tis a clacks for you, Mistress Weatherwax! It’s only the third one we’ve ever had!’ Shawn beamed at the thought of being so close to the cutting edge of technology.
    â€˜What’s one of them things?’ Granny demanded.
    â€˜It’s like a letter that’s taken to bits and sent through the air,’ said Sean.
    â€˜By them towers I keep flyin’ into?’
    â€˜That’s right, Mistress Weatherwax.’
    â€˜They move ’em around at night, you know,’ said Granny. She took the paper.
    â€˜Er … I don’t think they do …’ Shawn ventured.
    â€˜Oh, so I don’t know how to fly a broomstick right, do I?’ said Granny, her eyes glinting.
    â€˜Actually, yes, I’ve remembered,’ said Shawn quickly. ‘They move them around all the time . On carts. Big, big carts. They …’
    â€˜Yes, yes,’ said Granny, sitting on a stump. ‘Be quiet now, I’m readin’…’
    The forest went silent, except for the occasional shuffling of paper.
    Finally, Granny Weatherwax finished. She sniffed. Birdsong came back into the forest.
    â€˜Silly old fools think they can’t see the wood for the trees, and the trees are the wood,’ she muttered. ‘Cost a lot, does it, sendin’ messages like this?’
    â€˜That message,’ said Shawn, in awe, ‘cost more than 600 dollars! I counted the words! Wizards must be made of money!’
    â€˜Well, I ain’t,’ said the witch. ‘How much is one word?’
    â€˜Five pence for the sending and five pence the first word,’ said Shawn, promptly.
    â€˜Ah,’ said Granny. She frowned in concentration, and her lips moved silently. ‘I’ve never been one for numbers,’ she said, ‘but I reckon that comes to … sixpence and one half-penny?’
    Sean knew his witches. It was best to give in right at the start.
    â€˜That’s right,’ he said.
    â€˜You have a pencil?’ said Granny. Shawn handed it over. With great care, the witch printed some block capitals on the back of one of the pages, and gave it to him.
    â€˜That’s all?’ he said.
    â€˜Long question, short answer,’ said Granny, as it if was some universal truth. ‘Was there anything else?’
    Well, there might be the money, Sean thought. But in her own localised way, Granny Weatherwax had an academic position in these matters. Witches took the view that they helped society in all kinds of ways which couldn’t easily be explained but would become obvious if they stopped doing them, and that it was worth six pence and one half-penny not to find out what these were.
    He didn’t get his pencil back.
    The hole into L-space was quite obvious now. It fascinated Dr Dee, who was confidently expecting angels to come out of it, although all it had produced so far was an ape.
    The wizards’ automatic response to any problem was to see if there was a book about it. L-space was providing plenty of books. The difficulty, however, was finding the ones that applied to the current history; when you potentially know everything, it’s hard to find anything you want to know.
    â€˜So let’s see where we are now, shall we?’ said Ridcully, after a while. ‘The last known books in this leg of the trousers of time are due to be written in—?’
    â€˜About a hundred years’ time,’ said the Lecturer in Recent Runes, looking at his notes. ‘Just before the collapse of civilisation, such as it is. Then there’s fire, famine, war … all the usual stuff.’
    â€˜Hex says people here are back to living in villages when the asteroid hits,’ said Ponder. ‘Things are rather better on one or two other continents, but no one even sees it coming.’
    â€˜There have been periods like it before,’ said the Dean. ‘But as far as we can tell, in the area where we are now there were always small isolated groups of people who preserved what books there were.’
    â€˜Ah. Our kind of people,’ said Ridcully.
    â€˜Afraid not,’ said the Dean. ‘Religious.’
    â€˜Oh