Twenty-two Thousand Pounds for a Book!

 ...and it was worth it. 

 If you own a copy of Sir Isaac Newton's Mathematical Principles of Natural Philosophy, that is.

Here he is. Our buddy.

An extremely-rare first edition of Newton's 1729 book was found among other books on a (you guessed it) bookshelf in an East Wales house being cleared out. The auctioneer said he nearly "fell off my seat" when he realized what it was. 

   Newton (1643-1727) had died in his sleep by the time this edition was published.   (He may have been poisoned from mercury ingested from his scientific experiments.) Principia Mathematica, as it became known, was first published in 1687. (Actually, its full name was Philosophiae Naturalis Principia Mathematica.)

Photos from Dominic Winter Auctions

A second edition was published in 1713, using Newton's corrections. I'm not sure where this edition stands -- but believe it was the third.

Appraisal estimate was 15,000-20,000, so if the buyer's premium is not taken into account, final price is roughly in the ballpark. (In case you're wondering, the gaveled price equals a little more than $28,000 USD.)

 According to the auctioneer:

He said the "lucky seller" was "jumping around and punching the air" when they found out they had hit the "jackpot".

"It was on their shelves and they were looking for things to sell while they were in lockdown." he said.

"It's two volumes and if there's one page missing, it all goes out the window so they came and watched me collate it and spent 40 nervous minutes until I closed the second volume and said it's complete and worth £15k."

Makes you wonder -- why didn't the seller remember it was there? Dusty volumes, inherited from the family? A thrift shop buy?

Guess I'd better start looking.

Newton's own copy of the 1687 Principia, from Trinity College's (Cambridge) collection.
He had blank pages bound into the book, to make it easier
to add handwritten corrections. (Wikipedia)