Milkmaids' Hands

Teo worked out the size of the world that night, by candlelight, in a boathouse full of sleeping people, because he could not sleep and could not think about anything else.

It was not difficult, in the end. It was only careful.

Nell's stick had been as long as her forearm, and her shadow, at noon on the longest day, had been a certain fraction of it. His own stick, on the hill in the Ashlands, had been as long as his forearm, and his shadow a smaller fraction. The lengths of the sticks did not matter. Only the fractions did... the shape of the little triangle between the stick and the shadow and the sun. Teo drew both triangles on the back of the scrap of paper, very large, as carefully as he could, and measured the angle at the top of each with the marked board he had used for the Pole Star.

The sun at noon had stood a little over four and a half degrees higher in the sky over his hill than over Nell's roof.

So, between Calder Reach and the hill, the world had curved by four and a half degrees. One part in eighty of a whole circle.

Then Bram's cord. Teo unrolled it across the floor of the boathouse in the candlelight, and went through it knot by knot with the strip of bark on which he had scratched, every evening, the direction they had travelled that day. South down the river. East along the road. South again, where the road bent. North after the dust storm, but that was after the hill, so it did not count. He did not have a map. He had memory, and a plank, and the sun. He guessed... honestly, the way Bram had told him to. So many paces south. So many east. So much he was not sure of.

And when he had done it all, and multiplied the southward paces by eighty, he had a number.

Fifty-two million of Bram's paces, give or take a few million. All the way around the world.

Teo sat back against the wall and stared at it.

Then he pulled the red book out of his pack and turned to the chapter on measuring, where the Makers' units were explained, and the Makers' metre, and how long it was compared to the width of a man's hand and the length of a stride. A grown man's walking pace, the red book said, was a little less than a metre. Three quarters of one, perhaps, for a big man walking steadily beside a mule.

Fifty-two million paces. Times three quarters of a metre.

Thirty-nine thousand kilometres. Give or take a few thousand.

And on the next page, the red book said, in plain black letters, that the distance around the Earth at its widest was a little over forty thousand.

Teo looked at the two numbers for a very long time.

He had been wrong. Of course he had. He had guessed the directions and guessed the length of a pace, and the board was crooked, and his memory was imperfect. He was wrong by perhaps two parts in a hundred. Perhaps five. He could not know exactly.

But a cart-man and a ferryman and a ten-year-old girl, with two sticks and a knotted string, had measured the whole world.

'...Eratosthenes,' he thought, 'you would have liked Nell.'

He fell asleep against the wall a little before dawn, with the numbers on his lap, and dreamed of shadows.

Bram woke him with a cup of something hot and bitter and a face like a closed door.

"Ma's cows," he said.

Teo blinked up at him stupidly.

"What?"

Bram crouched down beside him. It took a while. Bram crouched the way a cliff collapses. When he was settled, he looked Teo in the eye and spoke slowly, the way he always did, as if each word had to be carried up from somewhere deep.

"Last night. The old man said, if you live through the red pox once, it never takes you again. Everyone knows that." He paused. "Well. Everyone in the Fens knows something else too."

Teo was awake now.

"Tell me."

"Milkmaids," said Bram. "In the Fens. They never get the red pox. Never. The red pox has come to the Fens three times since my grandmother was a girl, and it took the farmers, and the fishermen, and the children, and the old. But not the girls who milk the cows." He held up one huge hand and turned it over, slowly, showing the back of it and the palm. "Every winter, the cows get blisters. On the udders. Small ones. Cow-blister, we call it. It isn't much. And the milkmaids catch it on their hands from the milking. A few spots. A little fever, sometimes. Then it's gone. And after that..."

"They never get the red pox," Teo said slowly.

"Never."

Teo stared at him.

Then he was on his feet, scrambling for his pack, tipping it out across the floor of the boathouse... the brass telescope, the strips of bark, Ruth's notebook, the brass button... and the red book. He flipped it open to the index at the back with fingers that would not work properly. Fevers. Infection. Immunity. He had seen the word in the index under the mountain, and had not had time to read the chapter. He found it now. Chapter 11. Preventing Disease: Immunity and Vaccination.

He began to read aloud.

Bram sat and listened. Hesk woke, and listened. Mira woke, and sat up, and listened with her blanket wrapped around her shoulders and her eyes growing wider and wider. Nell woke last, and complained, and then stopped complaining and listened too.

The body was not helpless, the red book said. That was the first thing. When the small lives got inside it — the bacteria, the viruses — the body fought back. It had defenders, tiny living things in the blood, too small to see even through a bead of glass. And those defenders could learn. The first time they met a particular sickness, they were slow. They did not know its shape. They had to fumble and search and try, and while they did, the sickness grew, and sometimes it won. But if the body lived... the defenders remembered. They remembered the exact shape of the thing that had attacked them, the way a hand remembers the shape of a key. And if that same sickness ever came back, they knew it at once, and destroyed it before it could take hold.

That was why a pox survivor never caught the pox again. The body remembered.

And then the red book told a story.

In the 1700s, smallpox was one of the deadliest diseases in the world, killing as many as one in three of those infected. In the English countryside, it was commonly said that dairymaids who had caught cowpox, a mild disease of cattle, did not catch smallpox. In 1796, the English doctor Edward Jenner decided to test this. He took material from a cowpox blister on the hand of a dairymaid named Sarah Nelmes, and scratched it into the arm of a boy named James Phipps. The boy developed a mild fever and a single blister, and recovered. Several weeks later, Jenner deliberately exposed him to smallpox. The boy did not become ill.

Cowpox and smallpox are close relatives. Their shapes are similar enough that the body's defenders, having learned to recognise cowpox, also recognise smallpox. Jenner called his method 'vaccination,' from the Latin word 'vacca,' meaning cow.

Vaccination spread around the world. In 1980, after a long global campaign, smallpox was declared eradicated... the first and only human disease to be wiped out entirely.

Teo stopped there. He looked up from the page.

Nobody said anything for a long time.

"Wiped out," Mira said at last, very softly. "They wiped it out. The whole world. With a scratch from a cow."

"Then how is it back?" said Nell.

Teo looked down at the page again. Below the chapter, someone had written in the margin, by hand, in neat, slanting ink that he knew very well by now.

If you are reading this after the collapse, and a pox disease has returned... it may be smallpox, from a forgotten sample somewhere, or one of its many cousins, which still live in animals. It doesn't matter which. The method should still work. Look for cowpox in your cattle. Look for people who caught it and never got the pox. They are your proof. R.

Teo closed the book very gently.

He looked at Bram.

Bram looked back at him, and nodded slowly, as if Teo had said something aloud.

"Ma's cows," he said again.

"Do they have it now? This winter?"

"Every winter. Some of them." Bram was already standing up. "And my cousin Hessa milks them. Her hands are covered in it."

He reached for his coat.

"Three days down the river," he said. "Three days back. Less, if the river's kind."

"Bram..."

"I know what to bring," Bram said. "The red book said. Stuff from inside a blister. On a thread. Or a bit of cloth. Kept cool." He shrugged his huge shoulders into his coat. "I'll bring a lot."

And before anyone could say another word, he was gone, out into the grey dawn, and they heard the soft splash of his pole in the water as the barge slid away down the river.

Teo sat in the boathouse with the red book on his knees, and looked at the scrap of paper with the shadow measurements, and at the closed door.

Six days. Less, if the river was kind.

He thought of the red cloths nailed on every door in the Sump. Of the pyres burning in Saint Orlen's Square. Of three hundred sick in the Mercy House, and four acolytes, and Cobb, who was seventeen.

Then he thought of a boy called James Phipps, who had been eight years old, and the son of a gardener, and who had had no say at all in any of it.

'...Ah,' he thought slowly. 'Damn.'

Mira was watching him from across the room. She had seen it too. He could tell from her face.

"The red book says Jenner tested it," she said quietly, "by putting the pox into a child."

"Yes."

"On purpose."

"Yes."

Mira's jaw tightened.

"Then before Bram gets back," she said, "you and I are going to have a very long talk about who we test it on."