I was pleased to be invited to speak recently at the Folger Shakespeare Library in Washington for the opening of "Ships, Clocks & Stars: The Quest for Longitude." Having traveled to England last summer to see the exhibition's first iteration, I wanted to help welcome the items to the States. The numerous scientific instruments and portraits, including one of 18th-century clockmaker John "Longitude" Harrison, look splendid in the Folger's Great Hall, their new temporary home. When I arrived at the library on March 19, about an hour ahead of the two hundred invited guests, a pleasant surprise made me discard my prepared remarks. I had intended to say that the sea clocks at the heart of the show were all replicas, standing in for the venerated originals that reside at the National Maritime Museum in Greenwich as star tourist attractions. I meant to praise the copies for being fully functional and exact in every detail. I wanted to make the point that although the originals were not allowed out of the UK, the replicas could tour as their inventor's ambassadors, to be seen and appreciated all over the world. But there at the Folger, staring back at me from one of the display cases, was Harrison's celebrated fourth timekeeper -- the original H-4 -- the very "Watch" that had solved the longitude problem.
H-4 was made for travel. It crisscrossed the Atlantic twice in the 176os to prove its merit on ocean trials, but it had not gone anywhere since 1964, when the Admiralty lent it to the U. S. Naval Observatory. How happy I was to see it again.
I like to think Harrison would be pleased with the replicas of his sea clocks. After all, he built them as prototypes, and hoped the best design would multiply to occupy every vessel in the Royal Navy. I doubt he foresaw H-4's future as a museum piece. It has become one only because it answered the need so well.