Ordinary men had dreamed it up and put it together, building towers on rafts in swamps and across the frozen spires of mountains. They’d cursed and, worse, used logarithms. They’d waded through rivers and dabbled in trigonometry. They hadn’t dreamed, in the way people usually used the word, but they’d imagined a different world, and bent metal round it. And out of all the sweat and swearing and mathematics had come this… thing, dropping words across the sky as softly as starlight.