Isaac Newton (22 page)

W
HEN THE SEVENTEENTH CENTURY ENDED
, the published work of Isaac Newton amounted to little more than the several hundred copies of the
Principia
, most in England, a few scattered on the Continent. They were not much read, but scarcity made them valuable. Before a second edition was ready (in 1713, a quarter-century after first publication) a copy cost two guineas. At least one student saved his money and made a copy by hand.
¹
Newton’s nascent legend diffused only by word of mouth in a tiny community. When an anonymous solution to an esoteric geometry problem made its way to Holland, Johann Bernoulli announced that he recognized the solver “
ex ungue leonem
”—the lion by his claw.
²
In Berlin, Leibniz told the Queen of Prussia that in mathematics there was all previous history, from the beginning of the world, and then there was Newton; and that Newton’s was the better half.
³
Tsar Peter of Russia traveled to England in 1698 eager to see several phenomena: shipbuilding, the Greenwich Observatory, the Mint, and Isaac Newton.
⁴

The Royal Society was becalmed, its finances ragged, its membership dwindling. Hooke still dominated. Even living
in London, Newton mostly stayed away. Yet numerical thinking was in vogue—calculation of all kinds was permeating the life of the polity—and it conjured Newton’s name above all others. Mariners, architects, and gamblers were understood to depend on mathematical methods. Mathematics had become a pillar raising up the glory and honor of England, “the Academy of the Universe.”
⁵
John Arbuthnot published his
Essay on the Usefulness of Mathematical Learning
—a study which, he noted, seems to require “a particular genius and turn of head,… few are so happy to be born with.” The incomparable Mr. Newton had now discovered “the grand secret of the whole Machine.” And he assured his readers that the world was made of
number, weight, and measure
—echoing the Wisdom of Solomon as well as William Petty, the author of another new tract,
Political Arithmetick
.
⁶
Petty proposed the application of number to affairs of state and trade; the word
œconomick
barely existed, but he and like-minded scholars were counting what had not been counted before: populations, life expectancy, shipping tonnage, and the national income. Political arithmetic promised wonders, in a technological age:

One Man with a Mill can grind as much Corn, as twenty can pound in a Mortar; one Printer can make as many Copies, as an Hundred Men can write by hand; one Horse can carry upon Wheels, as much as Five upon their Backs; and in a Boat, or upon Ice, as Twenty.
⁷

A decisive technology, and the most venerable example of standard measure, was the coin. Petty reckoned “the whole Cash of England” at about six million pounds, circulating
among perhaps six million souls, and by intricate calculation he showed that this was “Mony sufficient to drive the Trade of the Nation.”

By the end of the century, though, England’s money faced a crisis. The silver penny had been the base unit of value for a millennium; for half that time, the only unit. Now gold had joined silver in supporting a vivarium of changing species: groats, shillings, farthings, crowns, guineas. That grand new coin, the guinea, was supposed to be worth twenty shillings, but its value fluctuated unpredictably, as did the price of silver. Untold quantities of English coin were counterfeit. Even more were shrunken in weight and value: worn by decades of handling or deliberately trimmed at the edges by professional clippers, who then made bullion of their accumulated shards. So for thirty years, new machines, powered by horses and men—the mechanisms guarded as a state secret
⁸
—had milled a coinage with an ornamented rim to foil the clippers. A mongrel currency was the result. No one would spend a new coin willingly; these were mostly hoarded or, worse, melted down for export to France. “Let one money pass throughout the king’s dominion, and that let no man refuse,” King Edgar had said, centralizing England’s coinage in the tenth century. “Let one measure and one weight be used, such as is observed in London.” No more. The melting houses and press rooms of the Mint, just inside the western rampart of the Tower of London, fell nearly silent as the 1690s began. Most coins circulating were blurry hammered silver, debased, mistrusted, and older than the hands through which they passed.

The crown called for guidance from eminent citizens,
Locke, Wren, and Newton among them. Wren proposed a decimal system; he was ignored. The new Chancellor of the Exchequer, Charles Montague, set a radical program in motion: a complete recoinage—all old coins to be withdrawn from circulation. Montague had known Newton at Cambridge and with this support the king named him Warden of the Mint in April 1696, just as the recoinage began. Newton supervised an urgent industrial project, charcoal fires burning around the clock, teams of horses and men crowding in upon one another, garrisoned soldiers standing watch. It was a tumultuous time at the Tower and in London: the terms of the recoinage had strangled the supply of money essential to daily commerce and, not incidentally, effected a transfer of national wealth from the poor to the rich.

Newton grew rich himself, as Warden and then, from 1700 onward, Master. (From his first months he complained to the Treasury about his remuneration,
⁹
but as Master he received not only a salary of £500 but also a percentage of every pound coined, and these sums were far greater.) He found a house in Jermyn Street, bought luxurious, mainly crimson furniture,
¹⁰
engaged servants, and invited his twenty-year-old niece, Catherine Barton, the daughter of his half-sister, to live with him as housekeeper. She became renowned in London society for beauty and charm. Jonathan Swift was an admirer and frequent visitor. Within a half-decade she became the lover of Newton’s patron Montague, by now the Earl of Halifax.
¹¹

By tradition the Mint posts offered easy income; Montague had promised Newton “ ’tis worth five or six hundred pounds per An, and has not too much bus’nesse to require
more attendance than you may spare.”
¹²
Newton did not mind treating his professorship as a sinecure—he drew his Cambridge salary in absentia—but he ran the Mint until his death, with diligence and even ferocity. He was, after all, the master of melters and assayers and metallurgists who multiplied gold and silver on a scale that alchemists could only dream of. He wrestled with issues of unformed monetary theory and international currency.
¹³
There was nothing lofty about the requisite arithmetic, yet few could have persevered through the intricacies of accounting:

The Assaymasters weights are 1, 2, 3, 6, 11, 12.… The weight 12 is about 16 or 20 grains more or less as he pleases.… His scales turn with the 128
^th
part of a grain, that is with the 2560
^th
part of the weight 12 which answers to less then the 10
^th
part of a penny weight.… The Melter runs from 600 or 700 to 800 lb of late 1000 lb weight of silver in a pot & melts 3 potts a day.… The pots shrink in the fire … 4 Millers, 12 horses two Horskeepers, 3 Cutters, 2 Flatters, 8 sizers one Nealer, thre Blanchers, two Markers, two Presses with fourteen labourers to pull them.…
¹⁴

In pursuing clippers and counterfeiters, he called on long-nurtured reserves of Puritan anger and righteousness. False coinage was a capital crime, high treason. Jane Housden and Mary Pitman, for example, were condemned (but pardoned) after having been caught with coining tools and trying to escape by dropping a parcel of counterfeit money into the Thames.
¹⁵
Newton often opposed such pardons. Counterfeiting was difficult to prove; he had himself made a
Justice of the Peace and oversaw prosecutions himself, all the way to the gallows. William Chaloner not only coined his own guineas but tried to cover his tracks by accusing the Mint of making its own false money. Newton, managing a network of agents and prison informers, ensured that he was hanged. He ignored the convict’s final plea:

Some body must have lost something to prove the Thiefe Some person robbd to prove the highwayman … Save me from being murthered O Dear Sr do this mercifull deed O my offending you has brought this upon me … O God my God I shall be murderd unless you wave me O I hope God will move your heart with mercy and pitty.…
¹⁶

Newton did not consider the uttering of bad money to be a victimless crime; he took it personally. For that matter, the crown held the Master of the Mint responsible for the weight and purity of its coinage, subject to enormous fines. At intervals he underwent the so-called Trial of the Pyx, named for the official coin chest, the pyx, protected by three independent locks and keys. A jury of the Goldsmiths’ Company would test select coins “by fire, by water by touch, or by weight or by all or by any of them,” Newton noted in a memorandum he drafted and redrafted eight times.
¹⁷
Then, with solemn ceremony, it would present the King’s Council with the verdict. Newton prepared carefully for these trials, carrying out his own assays. They showed that he had brought the standardization of England’s coins to new heights of exactness. For the coronation of Queen Anne, in 1702, he manufactured medals of gold and silver, for which he billed the Treasury, twice, precisely £2,485
18s. 3½
d
.
¹⁸
It was three years later, by Her Majesty’s Special Grace, that he was knighted.

A portent of future trouble came from Leibniz, by second hand: “to Mr. Newton, that man of great mind, my most devoted greeting”—and “another matter, not only did I recognize that the most profound Newton’s Method of Fluxions was like my differential method, but I said so … and I also informed others.”
¹⁹
In passing this on, the elderly mathematician John Wallis begged Newton to let some of his treasure out from the darkness. Newton was seen now as the curator of a hoard of knowledge, its extent unknown. Wallis told Newton he owed to the public his hypothesis of light and color, which Wallis knew he had suppressed for more than thirty years, and much more—a full optical treatise. “You say, you dare not yet publish it,” Wallis argued. “And why not yet? Or, if not now, when then? You adde, lest I create you some trouble. What trouble now, more then at another time?… Mean while, you loose the Reputation of it, and we the Benefit.”

His return to the Royal Society had waited, all these years, for Hooke’s exit. Hooke died in March 1703; within months Newton was chosen president. Past presidents had often been honorary, political figures. Newton seized power now and exercised it authoritatively. He quickly named his own Curator of Experiments. As president he attended almost every meeting; he commented from the chair on the reading of almost every paper.
²⁰
He asserted control over the selection of council members. He shored up the society’s sagging finances, in part from his own pocket. He
imposed a rule that the royal mace be displayed when and only when he was presiding.

With Hooke dead, he also finally took Wallis’s advice and released for publication his second great work—in English, rather than Latin,
²¹
and, more important, in prose rather than mathematics. This time he needed no editor. He had three “books” based on his work from thirty years earlier on the nature of light and color: the geometry of reflection and refraction; how lenses form images; and the workings of the eye and the telescope. The origin of whiteness; prisms; the rainbow. He added much more, in the form of “Queries”: queries on heat; queries on the ether; occult qualities, action at a distance, inertia. For good measure he included a pair of mathematical papers, the first he ever published. He titled the book
Opticks
—or,
a Treatise on the Reflexions, Refractions, Inflexions and Colours of Light
. He presented it to the Royal Society with an “Advertisement” in which he explained why he had suppressed this work since 1675. The reason: “To avoid being engaged in Disputes.”
²²

Not only had Hooke died but the world had changed. Newton’s style, integrating theories with mathematical experimentation, had become familiar to philosophers, and they accepted readily the same propositions that had stirred skepticism and scorn in the 1670s. In the
Opticks
Newton described his experiments vividly and revealed far more of his working style—at least, a plausible working style—than in the
Principia
. He leaped across optical wonders as across stepping stones: from the trigonometry of refraction to the use of spectacles and mirrors; from thin transparent plates to bubbles; from the composition of the rainbow to the refraction of crystals. Much of the available data was raw
and imprecise, but he shrank from nothing: friction, heat, putrefaction; the emission of light when bodies burn and when their parts vibrate. He considered the mysterious property called “electricity”—a vapor, or fluid, or vital force that seemed to arise from the excitation of glass, or cloth, as in his 1675 experiment with bits of paper.

But was light to be understood as waves or particles? He still believed, hypothetically, that light was a stream of material particles, but he explored wavy-seeming phenomena, too: “Do not rays of light move sometimes like an eel?” With Hooke buried, Newton also buried the ether as a medium that might vibrate with light waves, as a pond carries waves when struck by a stone. Such an ether would interfere with the planets’ permanent motion, otherwise so perfectly established now.