Chelsea, London
November 1834

For the first time in the history of our acquaintance, I do not want to visit Mary Somerville: not after this news of a possible husband. But I cannot undo the arrangement we have made without seeming rude, and so, feeling a despondence that I do not usually associate with our time together, I arrive at her house in Chelsea just as it is growing dark.

‘Oh, Ada, did your mother tell you?’ says Mrs Somerville, greeting me at the door.

‘She told me,’ I say, rather woodenly.

‘It is very exciting news,’ says Mary, looking at my face. ‘No, Ada, it is. You need a husband. Someone who will look after you.’

‘As though I am incapable of looking after myself!’ I burst out.

‘It is not that you are incapable,’ says Mary Somerville. ‘Don’t be so melodramatic. You and Lord King are an excellent match; I am convinced of it.’

To my relief, however, we move on to other matters. I have brought with me Mr Babbage’s plans. ‘I want to consult with you about these diagrams,’ I say to Mrs Somerville. We are sitting side by side at the small parlour table. ‘Mr Babbage has written some notes here, and here, in the margin, and I would like to ask you about them.’

Mrs Somerville calls for a servant to attend to the lights, and when more lamps are lit in the damp little room and the fire built up into a diminutive furnace, I show her the notes. ‘Look,’ I say. ‘Babbage has identified two parts of the new machine, which he calls the “mill” and the “store”. These terms fascinate me. He is clearly referring to the cloth industry, is he not?’

Mary Somerville frowns. ‘Ye-es,’ she says. ‘Yes, I think he must be. But I don’t quite see... It is a little fanciful, is it not?’

‘I don’t think he is being fanciful,’ I say. ‘It is just a metaphor – a comparison. He is using one system to describe another – quite a useful thing to do, since the new system – the one he is designing – does not yet exist.’

‘I suppose so,’ says Mary, squinting at the page. ‘The mill is where the actual work is done.’

‘That’s right. The computations, if you will,’ I say, speaking rather slowly, though my heart seems to be beating unnaturally fast. ‘The store, meanwhile, is where the materials are kept. Babbage is proposing to separate the actions of the machine in order to facilitate its working.’

‘I don’t know that he is even sure what he is about, you know,’ interjects Mrs Somerville. She still seems doubtful.

‘And this large barrel here, he refers to as the “drum”,’ I say, pointing to the centre of one of the diagrams.

‘Yes: this is the bit he is struggling with. It would turn very much as a drum in a music box would, but in order to be able to control so many operations it would have to be a barrel of incredible size.’

Together, we puzzle over the designs, teacher and pupil, while the darkness grows beyond the window and mists gather outside that are so thick that I know I would not be able to see my own hand in front of me, if I were to venture outside. But inside it’s as warm as a fur-lined cloak – so much so that I find myself feeling dozy, dreamy, almost drifting off to sleep sometimes. Mary gets up once to fetch a book from a shelf, and then again to put more coal on the fire. I prop my head on my hands, feeling the ridge of my cheekbone, and allow my eyes to close...

At first, I see those round white stones on the dream-beach where I met my father. They are less like soup plates now. Their edges are ridged. They darken; now they are neither plates, nor stones, but wheels. Cogwheels, interlaced, and set in a circular shape around a central barrel – a drum – that continuously turns, slowly but with great regularity. It is the Analytical Engine at work – I know this, even though I cannot see every part of the machine clearly. It is like a gigantic music box: the sound that comes from it is harp music initially, before it turns into the kind of jaunty brass-band tune that one might hear at the seaside. I walk closer, and see that something is coming out of the machine – it looks like paper, but it is thicker; perhaps canvas, or... no. It is woven silk, in one of the most exquisitely coloured compositions that I have ever seen: calculations, and equations are written upon it, and, at the centre, in letters the colours of the rainbow, one word: imagination. This is not a machine that will simply calculate figures; it will be able to create too...

‘Ada! Ada, my goodness – Ada!’

Mary Somerville seizes me by the shoulders just as my head falls forward; her touch startles me, pulling me out of my reverie. Suddenly I am back in the small, damp room, aware of the fire grumbling in the grate, the scratch of the upholstered chair against my legs.

‘The loom,’ I whisper. ‘It is like Mr Jacquard’s loom.’

‘No, don’t talk,’ says Mary, fussing her hands about my face, my hair. ‘Come – come and lie down.’ She manoeuvres me over to the chaise longue; I protest, but she won’t hear any of it. ‘We’ll wait for Somerville. He’ll be back soon.’

‘Mr Babbage,’ I say hoarsely. ‘I must speak to him. I saw... I saw something, Mary... his machine, the Analytical Engine... it could be used for music, you know, and – oh, even the creation of pictures and words and poems... magical potential... they are not just numbers, you see...’

‘Not numbers? Ada, what are you talking about? I can’t understand you.’

‘They are not just numbers,’ I say again. ‘The numbers represent – oh, anything, anything at all... but he must use his knowledge of the loom. That is how it will work.’ I dissolve into a fit of weak coughing.

‘You are not making any sense, my dear,’ says Mary Somerville. ‘Try not to talk now, until Somerville arrives.’

‘Oh, Mary, I saw it...’

But she has gone from the room.

‘Her eyes were fairly staring out of her head,’ I hear her saying to Dr Somerville, out in the hall, when at last he arrives. ‘I’ve never seen anything like it. She’s really not herself; she must go home at once, and I am going to write to Lady Noel Byron to recommend an immediate stop to her studies. No; she is not herself at all.’

Not myself: it’s the last thing I think about; that I, Ada – according to Mary, at least – have ceased to become Ada.

If not my Ada-self, with my Ada-brain, who am I?

When Dr Somerville enters the room, with Mary fluttering at his side, I sit up and ask him exactly that.

I lie in bed for a week, two weeks, four. I am quite unable to do anything else.

Mamma stays by my bedside most days, although we do not say much to each other. Sometimes I feign sleep, not wanting, or not able, to talk to her. She reaches for my hand occasionally, and I allow her to hold it, wishing that I had not said as much as I did to her, the last time that we actually spoke. I hear her draw in her breath, with the sharpness of one who has just had some kind of unpleasant realisation. I wonder if she is going to speak, but she never does.

My nineteenth birthday comes unnoticed, and Christmas too, and the New Year thereafter. We return to Ealing, and I barely register this change of scenery, although Nanny Briggs will tell me afterward that Mamma felt that the country air would suit me better, and she was probably right.

I prefer my bedroom at Fordhook to the low-ceilinged Wimpole Street chamber. I think that I do breathe more easily. Doctors come and go; I hear them muttering instructions to Nanny Briggs, and to Mamma. I hear occasional snippets: nervous exhaustion... mustn’t trouble herself further with intellectual pursuits, not for a long time...

I hear Mamma say: ‘The fault, if there is any fault, must be mine.’

Sometimes I dream: the shapes of Babbage’s engines form in my head with all the transparency of ghosts; I see scenes from my childhood, and from recent years. . . pebbly beaches, and spa towns with their iron-rich waters... carriage journeys and roadside inns... conversations with Mamma over a hundred brioche-laden breakfasts... and dance-cards, and unsuitable suitors who care for nothing but my fortune... People whispering in corners of crowded rooms.

‘That’s Ada Byron, my dear. Oh, but she has grown so pale and ill.’

‘Whatever can the matter be?’

I think of my father. Strains of his verses come to me with all the suddenness of rainbows that burst out unpredicted from cloudy skyscapes. I see him: slightly lame, loose-trousered, shouldering his caged squirrel or scrawling a letter at his desk. I think of him on his deathbed too, sending me his blessings.

Sometimes I cry, and they are not the harsh, hollow tears that I wept when I watched the Palace of Westminster burning – more a muted dribble of tears that leave patches of moisture on my sheets to surprise me, later, as I sleep. For I do sleep; I sleep more than I have ever slept in all my life.

Sometimes I do not dream at all.