Eliza could not help laughing. “I do not think my description of the slender one is at all cruel. On the contrary, I believe he will succeed. To judge from that pile of letters, he has many powerful Englishmen behind him. To rally that many supporters while remaining close to the King is very difficult.” Eliza was hoping, now, that the Prince would let slip some bit of information about who those letter-writers were. But William perceived the gambit almost before she uttered the words, and looked away from her.

“It is very dangerous,” he said. “Rash. Insane. I wonder if I should trust a man who conceives such a desperate plan.”

A bit of a silence now. Then one of the logs in the fireplace gave way in a cascading series of pops and hisses.

“Are you asking me to do something about it?”

More silence, but this time the burden of response was on William. Eliza could relax, and watch his face. His face showed that he did not like being put in this position.

“I have something important for you to do at Versailles,” he admitted, “and cannot afford to send you to London to tend to Daniel Waterhouse. But, where he is concerned, you might be more useful in Versailles anyway.”

“I don’t understand.”

William opened his eyes wide, took a deep breath, and sighed it out, listening clinically to his own lungs. He sat up straighter, though his small hunched body was still overwhelmed by the chair, and looked alertly into the fire. “I can tell Waterhouse to be careful and he will say, ‘yes, sire,’ but it is all meaningless. He will not really be careful until he has something to live for.” William looked Eliza straight in the eye.

“You want me to give him that?”

“I cannot afford to lose him, and the men who put their signatures on these letters, because he suddenly decides he cares not whether he lives or dies. I want him to have some reason to care.”

“It is easily done.”

“Is it? I cannot think of a pretext for getting the two of you in the same room together.”

“I have another oddity, sire: I am interested in Natural Philosophy.”

“Ah yes, you stay with Huygens.”

“And Huygens has another friend in town just now, a Swiss mathematician named Fatio. He is young and ambitious and desperate to make contacts with the Royal Society. Daniel Waterhouse is the Secretary. I’ll set up a dinner.”

“That name Fatio is familiar,” William said distantly. “He has been pestering me, trying to set up an audience.”

“I’ll find out what he wants.”

“Good.”

“What of the other thing?”

“I beg your pardon?”

“You said you had something important for me to do at Versailles.”

“Yes. Come to me again before you leave and I’ll explain it. Now I am tired, tired of talking. The thing you must do there for me is pivotal, everything revolves around it, and I want to have my wits about me when I explain it to you.”

M. Descartes had found the way to have his conjectures and fictions taken for truths. And to those who read his Principles of Philosophy something happened like that which happens to those who read novels which please and make the same impression as true stories. The novelty of the images of his little particles and vortices are most agreeable. When I read the book… the first time, it seemed to me that everything proceeded perfectly; and when I found some difficulty, I believe it was my fault in not fully understanding his thought… But since then, having discovered in it from time to time things that are obviously false and others that are very improbable, I have rid myself entirely of the prepossession I had conceived, and I now find almost nothing in all his physics that I can accept as true…

–HUYGENS, P. 186 OFWESTFALL’S 1971

The Concept of Force in Newton’s Physics:

The Science of Dynamics in

the Seventeenth Century

CHRISTIAANHUYGENS SATat the head of the table, the perihelion of the ellipse, and Daniel Waterhouse sat at the opposite end, the aphelion. Nicolas Fatio de Duilliers and Eliza sat across from each other in between. A dinner of roast goose, ham, and winter vegetables was served up by various members of a family that had long been servants in this house. Eliza was the author of the seating plan. Huygens and Waterhouse must not sit next to each other or they’d fuse together and never say a word to the others. This way was better: Fatio would only want to talk to Waterhouse, who would only want to talk to Eliza, who would pretend she had ears only for Huygens, and so the guests would pursue each other round the table clockwise, and with a bit of luck, an actual conversation might eventuate.

It was near the time of the solstice, the sun had gone down in the middle of the afternoon, and their faces, lit up by a still-life of candles thrust into wax-crusted bottles, hung in the darkness like Moons of Jupiter. The ticking of Huygens’s clock-work at the other end of the room was distracting at first, but later became part of the fabric of space; like the beating of their hearts, they could hear it if they wanted to, its steady process reassured them that all was well while reminding them that time was moving onwards. It was difficult to be uncivilized in the company of so many clocks.

Daniel Waterhouse had arrived first and had immediately apologized to Eliza for having taken her for a house-servant earlier. But he had not dropped the other shoe and asked what she really was. She’d accepted his apology with tart amusement and then declined to offer any explanation. This was light flirtation of the most routine sort-at Versailles it would have elicited a roll of the eyes from anyone who had bothered to notice it. But it had been more than enough to plunge Waterhouse into utter consternation. Eliza found this slightly alarming.

He had tried again: “Mademoiselle, I would be less than…”

“Oh, speak English!” she’d said, in English. This had practically left him senseless: first, with surprise that she could speak English at all, then with alarm that she’d overheard his entire conversation with William Penn. “Now, what was it you were saying?”

He scrambled to remember what he had been saying. In a man half his age, to’ve been so flustered would have been adorable. As it stood, she was dismayed, wondering what would happen to this man the first time some French-trained countess got her talons into him. William had been right. Daniel Waterhouse was a Hazard to Navigation.

“Err… I’d be less than honest if, er…” he winced. “It sounded gallant in French. Pompous in English. I was wondering… the state of international relations being so troublous and relations ‘tween the sexes more so, and etiquette being an area in which I am weak… whether there was any pretext at all under which I might converse with you, or send letters, without giving offense.”

“Isn’t this dinner good enough?” she’d asked, flirtatiously mock-offended, and just then Fatio had arrived. In truth, she’d seen him coming across the Plein, and adjusted her timing accordingly. Waterhouse was obliged to stand off to one side and stew and draw up a great mental accompt of his failures and shortcomings while Eliza and Fatio enacted a greeting-ritual straight out of the Salon of Apollo at Versailles. This had much in common with a courtly dance, but with overtones of a duel; Eliza and Fatio were probing each other, emanating signals coded in dress, gesture, inflection, and emphasis, and watching with the brilliant alertness of sword-fighters to see whether the other had noticed, and how they’d respond. As one who’d lately come from the Court of the Sun King, Eliza held the high ground; the question was, what level of esteem should she accord Fatio? If he’d been Catholic, and French, and titled, this would have been settled before he came in the door. But he was Protestant, Swiss, and came from a gentle family of no particular rank. He was in his early twenties, Eliza guessed, though he tried to make himself older by wearing very good French clothes. He was not a handsome man: he had giant blue eyes below a high domelike forehead, but the lower half of his face was too small, his nose stuck out like a beak, and in general he had the exhausting intensity of a trapped bird.