one child. And when Judith was nine, a splinter from a shot that had come through the bulwarks of the Ardent in the Downs had taken her father in the right eye, and the sea had taken the sight of the left over the next five years by slow degrees, and he had come ashore for good, with a small pension and a great deal of time.
There was, in those years, a way for a man who knew his lunars and his logarithms to earn a little money at home. The Nautical Almanac was not computed at Greenwich. The Astronomer Royal laid down the rules and the comparer checked the work; but the figures themselves, the thousands upon thousands of positions of the moon and the planets for every day of a year three years distant, were computed by hand, at their own tables, in their own houses, by men in market towns and parsonages and back parlours all over England. Two computers worked every month, each independently of the other; the comparer set their sheets side by side, and wherever they differed one of them was wrong, and was fined, and set right. It was slow and solitary and ill paid. It was also, Thomas Penrose said, the one employment in England in which a man could be neither flattered nor bullied out of a correct answer.
He had applied, and been taken on. And for some three years he had done the work himself, with his good eye close to the page and a magnifying glass on a brass arm. And then the good eye had begun to go, and his daughter, who was by then twelve, had begun to read him the figures from the tables; and by thirteen she was writing them down for him; and by fifteen she was computing whole sheets while he checked her by memory and mental arithmetic in the chair by the fire, calling out carry your sign, Judy, or that is a bad six; make it plainer, or, very occasionally, good girl.
By eighteen, she was doing all of it. The comparer, an old Cornishman named Josiah Oakes who had known her father in the service, had come up to Lambeth one winter to find out why the Penrose sheets had suddenly become so much tidier, and had sat for three hours in the kitchen watching her work, and had gone away without saying anything to anybody. The sheets continued to go out under her father's name. The money continued to come back. Nobody at Greenwich asked.
Thomas Penrose had died two years ago, in the February, quietly, in the chair by the fire. Judith had gone to see Mr. Oakes the week after the funeral, in her black, and asked him whether she might continue.
He had looked at her a long while.