How Newton Hunted Counterfeiters

Coins at the time were minted by hand, so their edges were uneven. That created a lucrative practice: people clipped or filed a little silver off a coin, then put it back into circulation, and it still looked almost the same.

By the end of the century, this had become a crisis. There was less and less silver in circulation, coins weighed noticeably less than their face value, and trust in money was falling. The country was on the brink of a monetary crisis.

The operation was enormous. Old coins were withdrawn and reminted across the country, while the currency system faced major difficulties during the changeover.

Counterfeiting coins was considered one of the most serious crimes, and the punishment matched. Proving it was difficult, though: witnesses were needed, and those witnesses were accomplices.

He approached it methodically: he recruited informants in taverns, gathered testimony, personally conducted hundreds of interrogations, and secured convictions, seeing the cases through to the end, something unusual for an official of that era.

The most famous case was his showdown with a clever counterfeiter who accused him of bribery and escaped trouble several times. The case lasted for years and ended in a conviction.

For a long time, people dismissed this part of his biography: the view was that the great scientist had wasted years in government service. Today, it is seen differently, as a major government task that he successfully completed.