Wednesday, May 2, 2012

Newton and the Royal Mint

Sir Isaac Newton had a "day job" - Master of the Royal Mint, from 1699 until his death in 1727.

Today I received an email notice about an upcoming statistics seminar at the University of British Columbia - just across the water from here:

Tue 8th May 2012, 11:00am

Ari Belenkiy

The Master at the Royal Mint: How much money did Newton save Britain?

"From the extant statistical data, this paper reconstructs several episodes in the history of the Royal Mint during Isaac Newton’s tenure. We discuss four types of uncertainty embedded in the production of coins, extending S. Stigler’s work (1977) back in time. The thirteen Jury Verdicts in Trials of the Pyx for 1696-1727 allow judgment on the impartiality of the Jury at the trials. The Verdicts, together with several remarks by Newton in his correspondence with the Treasury, allow us to estimate the standard deviation σ in weights of individual guineas coined before and during Newton’s Mastership. This parameter, in turn, permits us to estimate the amount of money Newton saved Britain after he put a stop to the illegal practice by goldsmiths and bankers of culling heavy guineas and recoining them to their advantage; a conservative estimate for savings to the Crown is £41,510, and possibly three times as much. The procedure with which he likely improved coinage gives historical insight on how important statistical notions – standard deviation and sampling -- came to the forefront in practical matters: the former as a measure of variation of weights of coins, and the latter as a test of several coins to evaluate the quality of the entire population. Newton can be credited with the formal introduction of testing a small sample of coins, a pound in weight, in the trials of the Pyx from 1707 onwards, effectively reducing the size of admissible error. Even Newton’s “Cooling Law” could have been contrived for the purpose of reducing variation in the weight of coins during initial stages of the minting process.  Three open questions are posed in the Summary".
 Looks fascinating!

I see that the paper is listed as "forthcoming" on the Journal of the Royal Statistical Society - Series A website

© 2012, David E. Giles


  1. Thomas Levenson's book "Newton and the Counterfeiter" is quite a good popular history of this period in Newton's life, including a bit about his role in the Great Recoinage.

    1. Brian - thanks for the pointer.

    2. Brian, culling had nothing to do with counterfeiting or clipping. The latter two were businesses of poor. Culling was avocation of rich!

  2. There is an older account, J. Craig. Newton at the Mint. Cambridge University Press, 1946, which makes some interesting comparisons between Newton's personality as an academic (grumpy) and that at the Mint (a good judge and handler of men). I have summarised these, "Isaac Newton: Financial Regulator" on my blog at

    1. Tim: Thanks! Liked your own post, and your blog in general!

    2. Tim: Craig's account is often flawed. See my paper (already at the website of J Roy Stat Soc A) where I make explicit statements in this regard.


Note: Only a member of this blog may post a comment.