She said to Atal:
How long have there been mulefa?
And Atal said:
Thirty-three thousand years.
She was able to read Mary’s expressions by this time, or the most obvious of them at least, and she laughed at the way Mary’s jaw dropped. The mulefa’s laughter was free and joyful and so infectious that Mary usually had to join in, but now she remained serious and astounded and said:
How can you know so exactly? Do you have a history of all those years?
Oh yes, said Atal. Ever since we have had the sraf, we have had memory and wakefulness. Before that, we remembered nothing.
What happened to give you the sraf?
We discovered how to use the wheels. One day a creature with no name discovered a seedpod and began to play, and as she played she—
She?
She, yes. She had no name before then. She saw a snake coiling itself through the hole in a seedpod, and the snake said—
The snake spoke to her?
No, no! It is a make-like. The story tells that the snake said, “What do you know? What do you remember? What do you see ahead?” And she said, “Nothing, nothing, nothing.” So the snake said, “Put your foot through the hole in the seedpod where I was playing, and you will become wise.” So she put a foot in where the snake had been. And the oil entered her blood and helped her see more clearly than before, and the first thing she saw was the sraf. It was so strange and pleasant that she wanted to share it at once with her kindred. So she and her mate took the seedpods, and they discovered that they knew who they were, they knew they were mulefa and not grazers. They gave each other names. They named themselves mulefa. They named the seed tree, and all the creatures and plants.
Because they were different, said Mary.
Yes, they were. And so were their children, because as more seedpods fell, they showed their children how to use them. And when the children were old enough to ride the wheels, they began to generate the sraf as well, and the sraf came back with the oil and stayed with them. So they saw that they had to plant more seedpod trees for the sake of the oil, but the pods were so hard that they seldom germinated. So the first mulefa saw what they must do to help the trees, which was to ride on the wheels and break them, so mulefa and seedpod trees have always lived together.
Mary directly understood about a quarter of what Atal was saying, but by questioning and guessing she found out the rest quite accurately; and her own command of the language was increasing all the time. The more she learned, though, the more difficult it became, as each new thing she found out suggested half a dozen questions, each leading in a different direction.
But she pulled her mind after the subject of sraf, because that was the biggest; and that was why she thought about the mirror.
It was the comparison of sraf to the sparkles on water that suggested it. Reflected light like the glare off the sea was polarized; it might be that the shadow particles, when they behaved like waves as light did, were capable of being polarized, too.
I can’t see sraf as you can, she said, but I would like to make a mirror out of the sap lacquer, because I think that might help me see it.
Atal was excited by this idea, and they hauled in their net at once and began to gather what Mary needed. As a token of good luck there were three fine fish in the net.
The sap lacquer was a product of another and much smaller tree, which the mulefa cultivated for that purpose. By boiling the sap and dissolving it in the alcohol they made from distilled fruit juice, the mulefa made a substance like milk in consistency, and delicate amber in color, which they used as a varnish. They would put up to twenty coats on a base of wood or shell, letting each one cure under wet cloth before applying the next, and gradually build up a surface of great hardness and brilliance. They would usually make it opaque with various oxides, but sometimes they left it transparent, and that was what had interested Mary: because the clear amber-colored lacquer had the same curious property as the mineral known as Iceland spar. It split light rays in two, so that when you looked through it you saw double.
She wasn’t sure what she wanted to do, except that she knew that if she fooled around for long enough, without fretting, or nagging herself, she’d find out. She remembered quoting the words of the poet Keats to Lyra, and Lyra’s understanding at once that that was her own state of mind when she read the alethiometer—that was what Mary had to find now.
So she began by finding herself a more or less flat piece of a wood like pine, and grinding at the surface with a piece of sandstone (no metal: no planes) until it was as flat as she could make it. That was the method the mulefa used, and it worked well enough, with time and effort.
Then she visited the lacquer grove with Atal, having carefully explained what she was intending, and asked permission to take some sap. The mulefa were happy to let her, but too busy to be concerned. With Atal’s help she drew off some of the sticky, resinous sap, and then came the long process of boiling, dissolving, boiling again, until the varnish was ready to use.
The mulefa used pads of a cottony fiber from another plant to apply it, and following the instructions of a craftsman, she laboriously painted her mirror over and over again, seeing hardly any difference each time as the layer of lacquer was so thin, but letting it cure unhurriedly and finding gradually that the thickness was building up. She painted on over forty coats—she lost count—but by the time her lacquer had run out, the surface was at least five millimeters thick.
After the final layer came the polishing: a whole day of rubbing the surface gently, in smooth circular movements, until her arms ached and her head was throbbing and she could bear the labor no more.