This is a book census, a technique in History of the Book/Bibliography where historians try and track down every existing copy of an edition of a book and then attempt to reconstruct the “provenance” - the ownership history of a particular copy. It’s one of the best tools for getting at the “reception” of a particular work.
The main findings of the Principia study according to the NYT:
> An earlier census of the book, published in 1953, identified 189 copies worldwide. But a new survey by two scholars has found nearly 200 more — 386 copies in all, including ones far beyond England in Budapest; Oslo; Prague; Zagreb, Croatia; the Vatican; and Gdansk, Poland.
The most complete and well-known example of this study to date was Owen Gingrich’s census of copies of Copernicus’ de revolutionibus: https://books.google.com/books/about/The_Book_Nobody_Read.ht...
The main findings of the Principia study according to the NYT:
> An earlier census of the book, published in 1953, identified 189 copies worldwide. But a new survey by two scholars has found nearly 200 more — 386 copies in all, including ones far beyond England in Budapest; Oslo; Prague; Zagreb, Croatia; the Vatican; and Gdansk, Poland.
Is this “surprisingly” wide? All a matter of expectation, I suppose. The original scholarly article is open access so you can decide for yourself: https://www.tandfonline.com/doi/full/10.1080/00033790.2020.1...