A 132-year-old message in a bottle turned up on an Australian beach earlier this year, but it’s not a love note or a treasure map: it’s a science experiment.

Tonya Illman was walking the beach with a friend while they waited for her son’s car to be dug out from the soft sand. That’s when she saw it. “I saw something sticking out of the sand, so I went to take a closer look,” she told the Western Australian Museum. “It just looked like a lovely old bottle, so I picked it up thinking it might look good in my bookcase. My son’s girlfriend was the one who discovered the note when she went to tip the sand out.”

When the Illmans unrolled the damp sheet of paper, they found a printed form, filled out in very faint handwriting—in German.

“This bottle was thrown overboard on 12th June 1886, in 32 degrees, 49 minutes latitude South and 105 degrees, 25 minutes longitude from Greenwich East,” it read. “From: Barque ship Paula. Home (port): Elsfleth.”

The captain’s name was illegible, but the form noted that the Paula was “On her journey from: Cardiff [Wales] to: Macassar [modern-day Indonesia].” According to the coordinates on the form, the Paula’s crew had tossed the note overboard about 600 miles from shore in the Indian Ocean.

It turned up 132 years later in January 2018, half-buried in the sand of an Australian beach north of Wedge Island, about 100 miles north of the city of Perth. Researchers say the bottle probably washed ashore within a year of hitting the water, but ended up buried in damp sand until a storm uncovered it. If the bottle hadn’t been buried, the note might not have been preserved at all.

Old-school science

Illman’s husband Kym traced the form and the bottle to an oceanography experiment started by the German Naval Observatory in 1864. In an effort to map out faster shipping routes by plotting the world’s ocean currents, German ships tossed thousands of bottles overboard from 1864 to 1933, each one containing a form listing the date and coordinates of the message, along with the ship’s name, its home port, and the route it had been sailing at the time.

The back of the form asked the finder to record the date and location of the find and then return the form to the German Naval Observatory in Hamburg or to the nearest German consulate. Of the thousands of forms thrown into the world’s oceans during the 69-year program, only 662 had been recovered—at least 20 of them around the Australian coast. The last had turned up on the shores of Denmark on January 7, 1934, a few months after the project’s official end.

The Illmans’ find brought the total to 663, but first they had to confirm it.

“Extraordinary finds need extraordinary evidence to support them,” said Ross Anderson, assistant curator for maritime archaeology at the Western Australian Museum, where the Illmans took the bottle and the note for help with the research. Museum staff identified the “lovely old bottle” as a mid- to late-19th century Dutch gin bottle. And the paper rolled up inside looked like cheaply-made 19th century paper, the kind you’d expect a mass-produced government form to be printed on.

Anderson and his colleagues contacted historians in Germany and the Netherlands for more information, and they got very lucky. “Incredibly, an archival search in Germany found Paula’s original Meteorological Journal and there was an entry for 12 June 1886 made by the captain, recording a drift bottle having been thrown overboard,” said Anderson. And the handwriting in the Paula’s log was identical to the handwriting on the form.

The Illmans have loaned the bottle and the note to the Western Australian Museum, where it will spend the next two years on display.

Science keeps floating

Oceanographers are still trying to build a better understanding of ocean currents, especially how they interact with wind and waves, and the basic method hasn’t changed much in the last 132 years.

“The time-honored method is by releasing small floating objects and observing where the drift takes them,” wrote the authors of a 2012 paper which used data from the 1864-1933 German Naval Observatory bottles to study surface drift in the Southern Ocean.

More modern drift studies, however, now use satellite-tracked floats that don’t rely on luck or the cooperation of finders to get the data back to scientists. A 2015 paper compared two different float designs; the red float in the image followed the blue route on the map, while the orange spherical float followed the red route on the map.

But that doesn’t mean oceanographers will turn down a bit of luck when it arrives. Drift studies have also been done with buoyant cargoes that accidentally washed overboard at a known point, including Lego bricks and rubber ducks.