Hodinkee posted an intersting piece on the origin and definitions of a chronometer.

https://www.hodinkee.com/articles/wh...it-means-today

It covers a lot but near theend it gets the Thacker attribution probably well known to my dwellers of this area.

What is new is the theoory that Thacker never existed and his book was satire by a Mr. Arbuthnoy (I kid you not).

It's a very good read and very credible.