“I understand your question now,” Daniel said. “Astronomers used to explain the seeming retrograde movements of the planets by imagining a phantastic heavenly axle-tree fitted out with crystalline spheres. Now we know that in fact the planets move in smooth ellipses and that retrograde motion is an illusion created by the fact that we are making our observations from a moving platform.”
“Viz. the Earth.”
“If we could see the planets from some fixed frame of reference, the retrograde motion would disappear. And you, Roger, observing Newton’s wandering trajectory-one year devising new receipts for the Philosophic Mercury, the next hard at work on Conic Sections-are trying to figure out whether there might be some Reference Frame within which all of Isaac’s moves make some kind of damned sense.”
“Spoken like Newton himself,” Roger said.
“You want to know whether his recent work on gravitation is a change of subject, or merely a new point of view-a new way of perceiving the same old Topic.”
“ Nowyou are talking like Leibniz,” Roger said grumpily.
“And with good reason, for Newton and Leibniz are both working on the same problem, and have been since at least ’77,” Daniel said. “It is the problem that Descartes could not solve. It comes down to whether the collisions of those billiard balls can be explained by geometry and arithmetic-or do we need to go beyond pure thought and into Empirical and/or Metaphysical realms?”
“Shut up,” Roger said, “I’m working on a murderous headache as it is. I do not want to hear of metaphysics.” He seemed partly sincere-but he was keeping one eye on someone who was coming up behind Daniel. Daniel turned around and came face to face with-
“Mr. Hooke!” Roger said.
“M’lord.
“You, sir, taught this fellow to make thermometers!”
“So I did, m’lord.”
“I was just explaining to him that I wanted him to go up to Cambridge and gauge the heat of that town.”
“The entire country seems warm to me, m’lord,” said Hooke gravely, “in particular the eastern limb.”
“I hear that the warmth is spreading to the West country.”
“Here is a pretext, ” said the Marquis of Ravenscar, stuffing a sheaf of papers into Daniel’s right hip pocket, “and here is something for you to peruse on your journey-the latest from Leipzig.” He shoved something rather heavier into the left pocket. “Good night, fellow Philosophers!”
“Let us go and walk in the streets of London,” Hooke said to Daniel. He did not need to add: Most of which I laid out personally.
“RAVENSCAR HATED HIS COUSINJohn Comstock, ruined him, bought his house, and tore it down,” Hooke said, as if he’d been backed into a corner and forced to admit it, “but learned from him all the same! Why did John Comstock back the Royal Society in its early days? Because he was curious as to Natural Philosophy? Perhaps. Because Wilkins talked him into it? In part. But it cannot have escaped your notice that most of our experiments in those days-“
“Had something to do with gunpowder. Obviously.”
“ RogerComstock owns no gunpowder-factories. But his interest in the doings of our Society is no less pragmatic. Make no mistake. The French and the Papists are running the country now-are they running Newton?”
Daniel said nothing. After years of sparring with Hooke over gravitation, Isaac had soared far beyond Hooke’s reach since Halley’s visit.
“I see,” Daniel said finally. “Well, I must go north anyway, to play at being the Puritan Moses.”
“It would be worth an excursion to Cambridge, then, in order to-”
“In order to clear Newton’s name of any scurrilous accusations that might be made against him by jealous rivals,” Daniel said.
“I was going to say, in order to disentangle him from the foreign supporters of a doomed King,” Hooke said. “Good night, Daniel.” And with a few dragging steps he was swallowed up in the sulfurous fog.
THE ENTIRE COUNTRY SEEMS WARMto me… in particular the eastern limb.Hooke might throw accusations carelessly, but not words. Among men who peered through telescopes, “limb” meant the edge of a heavenly body’s disk, such as the moon’s crescent when it was illumined from the side. Setting out to the northeast the next day, Daniel glanced at a map of Essex, Suffolk, and Norfolk and noticed that they formed a semicircular limb, bounded by the Thames on the south and the Wash on the north, and in between them, bulging eastwards into the North Sea. A bright light kindled above the Hague would shine a hundred nautical miles across the sea and light up that entire sweep of coastline, setting it aglow like a crescent moon, like the alchemist’s symbol for silver. Silver was the element of the Moon, the complement and counterpart of the Sun, whose element was gold. And as the Sun King was now pouring much gold into England, the possible existence of a silvery lunar crescent just to the north of London had import. Roger had no patience with alchemical suppositions and superstitions, but politics he knew well.
The fifty-second parallel ran directly from Ipswich to the Hague, so any half-wit with a backstaff and an ephemeris could sail unerringly from one to the other and back. Daniel knew the territory well-the North Sea infiltrated the Suffolk coast with so many spreading rays of brackish water that when you gazed east at sunrise the terrain seemed to be crazed with rivers of light. It was impossible to travel up the coast proper. The road from London was situated ten to twenty miles inland, running more or less straight from Chelmsford to Colchester to Ipswich, and everything to the right side-between it and the sea-was hopeless, from the point of view of a King or anyone else who wanted to rule it: a long strip of fens diced up by estuaries and therefore equally impassable to horses and boats, easier to reach from Holland than from London. Staying there wasn’t so bad, and staying out was even better, but movement was rarely worth the trouble. Objects would not move in a resistive medium unless impelled by a powerful force-ergo, any travelers in that coastal strip had to be smugglers, drawn by profit and repulsed by laws, shipping England’s rude goods to Holland and importing Holland’s finished ones. So Daniel, like his brothers Sterling and Oliver and Raleigh before him, had spent much time in this territory as a youth, loading and unloading flat-bottomed Dutch boats lurking beneath weeping willows in dark river-courses.
The first part of the journey was like being nailed, with several other people, into a coffin borne through a coal-mine by epileptic pallbearers. But at Chelmsford some passengers got out of the carriage and thereafter the way became straight and level enough that Daniel could attempt to read. He took out the printed document that Roger had given him in the coffee-house. It was a copy of Acta Eruditorum, the scholarly rag that Leibniz had founded in his home town of Leipzig.
Leibniz had been trying for a long time to organize the smart Germans. The smart Britons tended to see this as a shabby mockery of the Royal Society, and the smart Frenchmen viewed it as a mawkish effort by the Doctor (who’d been living in Hanover since ’77) to hold up a flawed and tarnished mirror to the radiant intellectual life of Paris. While Daniel (reluctantly) saw some justice in these opinions, he suspected that Leibniz was mostly doing it simply because it was a good idea. At any rate Acta Eruditorum was Leibniz’s (hence Germany’s) answer to Journal des Savants, and it tended to convey the latest and best ideas coming from Germany-i.e., whatever Leibniz had been thinking about lately.