Message.

"Please state where and when this card was found, and then put it in the nearest Post Office," read the message. "You will be informed in reply where and when it was set adrift. Our object is to find out the direction of the deep currents of the North Sea."

The message in a bottle found by Andrew Leaper—certified by Guinness World Records on August 30 as the oldest ever recovered—belonged to a century-old science experiment. To study local ocean currents, Capt. C. Hunter Brown of the Glasgow School of Navigation set bottle number 646B adrift, along with 1,889 others, on June 10, 1914.

Read the rest at National Geographic.