In the spring of 1696, Isaac Newton — fifty-three years old, author of the Principia, and restless after three and a half decades in Cambridge — moved to London to become Warden of the Royal Mint, inside the Tower of London. His friend Charles Montagu, the Chancellor of the Exchequer, had arranged the post as a comfortable reward, assuring him it would not demand much of his time. Newton proceeded to treat it the way he treated everything else: as a problem to be solved completely.
He arrived in the middle of a currency catastrophe. England's older silver coins were hand-hammered, with irregular edges that invited "clipping" — shaving off slivers of silver to melt down — and after decades of it much of the money in circulation was far below its lawful weight, while counterfeits multiplied. This was not a mere nuisance: England was fighting an expensive war against Louis XIV's France, and paying armies abroad depended on silver that foreign merchants would accept at face value. Machine-milled coins had been introduced in 1662, some bearing the protective edge motto Decus et Tutamen, "an ornament and a safeguard", but good new coins were promptly hoarded or melted while bad ones circulated. Parliament's answer was the Great Recoinage of 1696: call in the entire silver coinage and strike it afresh. The philosopher John Locke won the argument over how — against the Treasury official William Lowndes, who wanted to devalue, Locke insisted the new coins keep the old standard. Branch mints were opened at Bristol, Chester, Exeter, Norwich and York, and the famous window tax was introduced in 1696 partly to pay for it all. Newton reorganised the Tower's production and multiplied the Mint's output severalfold; within about three years, millions of pounds' worth of new milled silver had been struck and the crisis had passed.
The warden turns detective
The Warden's other duty — prosecuting coiners and clippers — had been treated by his predecessors as beneath the office. Newton at first asked the Treasury to relieve him of it; refused, he took it up with alarming energy. Counterfeiting the coin was high treason, punishable by death, and Newton became a magistrate, recruited informers, paid undercover agents, and by the Mint's own records personally conducted more than a hundred interrogations of suspects, witnesses and prisoners — in the Tower, in Newgate gaol and, by some accounts, in the taverns of the underworld in disguise. His campaign sent a succession of coiners to the gallows.
The duel with Chaloner
The most brazen of them was William Chaloner, a onetime japanner of household goods who had risen to become one of London's most accomplished counterfeiters — and its cheekiest, boasting of the sham guineas he had put into circulation. Chaloner petitioned Parliament, claiming the Mint itself was corrupt and offering his own services to inspect and improve its methods; he publicly accused Newton's operation of abetting fraud. Newton's first attempt to convict him collapsed, and Chaloner walked free to boast about it. The Warden then spent the better part of two years methodically assembling witnesses from the criminal underworld. In March 1699 Chaloner was convicted of high treason and hanged at Tyburn, having written increasingly frantic letters begging Newton to save him. No reply survives.
Later in 1699 Newton was promoted to Master of the Mint, a post he held until his death in office in 1727, on his way to burial in Westminster Abbey — some thirty-one years at the Mint in all, longer than he had spent on the Principia and the calculus put together. The Mastership paid a fee on every coin struck and made him rich; his knighthood from Queen Anne in 1705 probably owed more to politics and the Mint than to gravity. And he left one more mark on money itself. In 1717 his report as Master fixed the golden guinea at twenty-one silver shillings — a rate that overvalued gold, quietly drained silver abroad, and helped nudge Britain towards a de facto gold standard long before Parliament made it official in the nineteenth century. Even Newton could still be fooled by a market, though: he lost heavily in the South Sea Bubble of 1720 — reportedly a five-figure sum — and the famous lament attributed to him — that he could calculate the motions of the heavenly bodies but not the madness of people — was only reported decades later, so treat it as legend with good tailoring.
The man who had reduced the heavens to law spent his last three decades enforcing it, shilling by shilling.
Quiz nuggets
- Newton joined the Royal Mint as Warden in 1696 and served as Master from 1699 until his death in 1727.
- Counterfeiting coin was high treason; Newton's great adversary William Chaloner was hanged at Tyburn in March 1699.
- The Great Recoinage of 1696 was part-funded by the newly introduced window tax.
- The edge motto Decus et Tutamen ("an ornament and a safeguard") was an anti-clipping measure on milled coins from 1662.
- Newton's 1717 valuation of the guinea at 21 shillings helped push Britain towards a de facto gold standard.