IN EARLY FEBRUARY 1699, a middle-ranking government official found himself a quiet corner of the Dogg pub. He was dressed appropriately. After almost three years on the job, he knew better than to dress for the Royal Society when he wished to pass unremarked in Holborn or Westminster.
The pub was, he hoped, a place where two men could speak discreetly. Big as London was, it could still be a very small town. Men employed in a given trade—legitimate or otherwise—tended to know one another.
The man he awaited came in. His companions would have had to hang back, keeping an eye on their charge from a distance. The newcomer knew the rules—as he should—given his current address: Newgate Jail.
The jailbird sat and started to speak.
There was someone, he said, he had been getting close to, a man who liked to talk. That man was cagey, and smart enough not to trust entirely those with whom he spoke—naturally enough given the nature of his companions, who, like him, were all awaiting trial. But after weeks and months in the cells, staring at the same faces, the monotony of prison life had got to him, and there was not much else to do but talk.
The official listened, increasingly impatient. What had the cellmate said? Did the informer have anything really worth hearing?
No, not quite ... perhaps. There was a tool, an engraved plate—you know?
The official knew.
It was hidden, the informer said—of course, for that was what he had been placed in the cell to learn: not just that the plate was hidden, but where.
It was not necessary to remind the jailbird that he lived or died at the official's choice.
The plate is hidden, the informer said, inside a wall or a hollow at one of the houses William Chaloner had last used for a run of counterfeit cash.
Which one?
He didn't know, but Chaloner had boasted that "it was never lookt for in such vacan[t] places."
The detective swallowed his irritation. He already knew that Chaloner was no fool. What he wanted now was something he could get his hands on.
The jailers picked up the hint. It was time to return their charge to Newgate, with orders to do better.
When they were gone, the other man left the pub on his own. He made his way back into the heart of the city, entering the Tower of London through the main west gate.
He turned left and crossed into the precincts of the Royal Mint. There he returned to his usual routine, interrogating another witness, reading over depositions, checking the confessions to be signed.
It was all part of the job, to weave a chain of evidence strong enough to hang William Chaloner—or any counterfeiter whom Isaac Newton, Warden of the Royal Mint, could discover.
Isaac Newton? The founder of modern science; the man recognized by his contemporaries—and ever since—as the greatest natural philosopher the world has ever seen? What had the man who had brought order to the cosmos to do with crime and punishment, the flash world of London's gin houses and tenements, bad money and worse faith?
Isaac Newton's first career, the only one most people remember, lasted thirty-five years. Throughout that period, he was a seemingly permanent fixture at Trinity College, Cambridge—first as a student, next as a fellow, and finally as Lucasian Professor of Mathematics. But in 1696 Newton came to London to take up the post of Warden of the Royal Mint. By law and tradition, the position required him to protect the King's currency, which meant that he was supposed to deter or capture anyone who dared to clip or counterfeit it. In practice, that made him a policeman—or rather, a criminal investigator, interrogator, and prosecutor rolled into one.
A more surprising candidate for the job would be hard to imagine. Newton, in both popular memory and the hagiography of his own time, did not get his hands dirty. He did not so much live as think—and he thought in realms far above those reached by ordinary minds. Alexander Pope captured contemporary sentiment about him in a famous couplet:
Nature and Nature's laws lay hid in night:
God said, Let Newton be! and all was light.
Newton lived, or was imagined to live, beyond the passions and chaos of daily life. It did not take long for his successors to canonize him as a saint in the transforming church of reason. It was no accident that on a 1766 visit to London, Benjamin Franklin commissioned a portrait of himself that shows him sitting at a desk, studying, while a bust of Newton watches over him.
Yet despite having no training or experience or evident interest in the management of men or things, Newton excelled as Warden of the Mint. He tracked, arrested, and prosecuted dozens of coiners and counterfeiters during the four years of his tenure. He knew—or rather, he learned very quickly—how to tangle his opponents in intricately woven webs of evidence, careless conversation, and betrayal. London's underworld had never confronted anyone like him, and most of its members were utterly unprepared to do battle with the most disciplined mind in Europe.
Most, but not all. In William Chaloner Newton found an adversary capable of challenging his own formidable intelligence. Chaloner was no petty criminal. His claimed production of thirty thousand pounds in counterfeit money represented a true fortune—as much as four million pounds in today's currency. He was literate enough to submit pamphlets on finance and the craft of manufacturing coins to Parliament and cunning enough to avoid prosecution for at least six years of a very ambitious criminal career. He was ferocious to a fault, with at least two deaths to his credit, and a profit made from each. Most of all, he was bold. He accused the new Warden of incompetence, even alleged fraud in his management of the Mint. Thus joined, the battle between them raged for more than two years. Before it was over, Newton had made of his pursuit of Chaloner a masterpiece of empirical research. And as he did so he revealed a persona at once less familiar and more coherent, more truly human than the Newton of the hagiographies—a man who not only propelled the transformation in ideas called the scientific revolution but who, along with his contemporaries, lived, thought, and felt them, day in and day out.
That transformation happened both within and to Isaac Newton. To become the man who could run the infamous Chaloner to ground, Newton had to master the habits of mind required for the task. That process, the making of perhaps the most unlikely detective on record, can be dated to the day a young man walked through the gates of a small town in Lincolnshire to further his education.