If this world wouldn’t allow clocks to work, she’d decided, she would damn well build her own. Never mind electronics, or even clockwork which was almost as much of a mystery to her. She’d gone back to basics.
The cat walked up somewhat stiffly, lay down beside her and inspected the rig. ‘If I may ask, Agnes – what on Earth are you doing?’
‘Can’t you tell? I’m making an hourglass. And I’m missing Joshua. He’d put together something for me in a couple of hours, in a polished wooden case, probably …’
The cat licked her paws. ‘There are a number of ways to tell the time. By a simple sundial for instance. Though that would take some weeks, at least, to calibrate.’
‘I intend to do that too. But I want some other way, independent of the sun. I want to measure the length of the day. Shi-mi, I know this sounds dumb.’
‘I travelled months on twains run by US Navy grunts. Believe me, nothing you say about mechanical matters will sound dumb to me. And I do know why you need to do this. We spoke of it before—’
‘I think there’s something wrong with time here,’ Agnes blurted. ‘The days are too short – or maybe too long. I don’t know. All I do know is I’m having trouble sleeping, and always have had. And as all our watches and clocks are either back home in Madison West 5 or out of bounds—’
‘My internal clocks are not accessible to me either.’
‘—and I don’t want to ask Lobsang because I think it would upset him if I started breaking the rules around here, I need to make some other kind of measurement. I figure that if I can measure an hour accurately, say, then I’ll stay awake for a day and a night, from dawn to dawn, and just count the hours, count how often I have to empty the bucket. It’s crude but better than nothing.’
‘Noon to noon would be better. Easier to mark accurately. A sundial would help you with that. And it may be more precise to have smaller buckets, measuring half-or quarter-hours … Or you could use both, to cross-check the measurements. But how can you be sure your hourglass measures a true hour in the first place?’
‘That’s my problem, all right.’ She showed the cat her wrist, her thumb pressed on a vein. ‘My resting pulse has always been pretty steady, fifty beats a minute.’
‘A strong heart.’
‘Yes. I assume Lobsang will have replicated that when he, umm, remade me.’
‘That is a very uncertain baseline.’
Agnes found it hard not to be sarcastic to a talking cat. ‘I suppose you have a better way?’
‘Yes. Build a pendulum.’
‘A what?’
‘A simple pendulum. A thread suspended from a beam, supporting a weight. The length of the thread determines the period of the swing. A length of thirty-nine inches will give you a period of two seconds, almost exactly. That’s if the pull of gravity here is the same as on the Datum, and when we arrived we measured that, among other parameters … A longer length would give you a longer period, more accuracy. You could use a reliable reference like that to build from. Make sand cups to measure a minute, combine them to get five minutes, thirty—’
Impulsively Agnes leaned over, cupped Shi-mi’s face, and kissed the top of her head. ‘Cat, you’re a genius.’
But Shi-mi shrank back from her touch.
Agnes immediately forgot about her high school science experiments. Shi-mi had never reacted like that before, not ever. ‘Shi-mi? What is it?’ She picked the cat up, though Shi-mi wriggled in faint protest, and inspected her body, felt her limbs – and probed her belly, where she found hard masses. ‘Are you ill?’
‘I am old, Agnes,’ the cat said, lying in her arms. ‘Or so I have been programmed to become. My body swarms with nanotech agents, ageing me day by day. And because I am old I am ill. I suffer from a meticulously simulated arthritis, and various of my organs have problems. A remarkable feat of artifice.’
‘Does it hurt?’
The cat said nothing.
‘Well, would you like something to be done?’ After only three years here, Agnes had not yet thought hard about her own future, the years when it would start to become odd if she did not show signs of age. She did know Lobsang had brought a suite of systems to allow them to adjust their appearance – but she also knew there were other options. ‘You don’t have to go through this. We could rebuild you. Fake your death. We could even call a twain and pretend it brought us another, younger cat.’
‘No. I am myself,’ Shi-mi said firmly. ‘I have long memories. I was made by the Black Corporation as a mere technology demonstrator. But I sailed with Joshua and Lobsang on their first journey together, to the High Meggers and beyond. I travelled with Captain Maggie Kauffman to the ends of the Long Earth. In these last years I have been Ben’s cat, nothing more, nothing less. I am not willing to discard all that.’
‘You wouldn’t have to. You’d still be yourself inside.’