By Marte Rommetveit

Old logbooks are important for climate science today, but even in the 1800s, amateur researchers used these weather observations to understand the ocean.

What drives a wealthy Danish-Norwegian general to delve into ship’s logs and become almost obsessed with understanding ocean currents in the 1800s? And why has this amateur researcher remained unknown until now?

To answer this, we must head down to the basement of the Danish National Archives in Copenhagen.
In the archives, around 700 shelf meters of old logbooks from the 17th century onwards are waiting to be digitized and used to write climate history.

However, researchers Ellen Krefting and Gard Paulsen at the University of Oslo have a different focus. They are looking for patterns and dynamics in the historical knowledge of the ocean and are interested in what they call “knowledge formats”:

“We are more concerned with the format of ship’s logs than their content, and have studied how these books have shaped our knowledge of the ocean,” explains Ellen Krefting, who is a professor of history of ideas.

For centuries, captains and mates on ships of a certain size have been required to fill out logbooks, also called ship’s logs or ship journals. In the logbooks, we find daily observations of weather, position, daily life, and dramatic events.

“These logbooks are machineries of knowledge and have had a very significant impact on our understanding of the sea and what knowledge is deemed important,” Krefting believes, and her colleague Paulsen adds:

“People did not keep ship’s logs to understand the sea, but we have discovered that others used them for that purpose much earlier than we previously thought.”

“Wow, what is this?”

As they search through the shelves at the Danish National Archives, the researchers suddenly discover a collection of data retrieved from old logbooks from the 1860s signed by H. Mathiesen.

“Wow, what is this?” we thought, and began to dig deeper, recounts Krefting.

His full name is Haagen Waldemar Mathisen, the illegitimate son of a wealthy Norwegian merchant. He has collected logbooks, organised them into a system, and created numerous tables, reminiscent of today’s Excel spreadsheets.

“He was a general in the Danish army and collected ship’s logs because he was so passionately interested in ocean currents,” says Krefting.

In the winter of 1864, he is at war and observes German troops marching directly over a marsh that usually does not freeze. That’s when he begins to develop his own theory about ocean currents, convinced that the climate is connected to the sea.

“Mathiesen is truly wonderful. I find it fantastic that a general could be interested in this in the 1800s,” says researcher Gard Paulsen.

Ocean science is older than we think

But it turns out that General Mathiesen is not the only amateur researcher looking to logbooks at that time.

“There were a whole bunch of them,” Krefting says.

This indicates that the systematic exploration of the ocean is not as recent as previously assumed.

“Ocean science, or oceanography, is often thought to have started in the 1870s, and we have believed that the knowledge of the ocean before that time was anything but scientific,” says Gard Paulsen.

But that is not correct. Although amateur researchers did not conduct experiments and scientific investigations, they gained knowledge by sitting at desks and systematizing observations made by ordinary people. Big data in the 1800s, indeed.

“It is therefore surprising for us that what we think of as a modern phenomenon, using older data to obtain systematic knowledge about wind and weather, was also something they were engaged in long ago,” Paulsen says.

Knowledge does not solve everything

The researchers are surprised by how stable the format of the ship’s logs has been over time. Logbooks from the early 1600s look quite similar to present day ones.

“Many types of knowledge about the ocean have become accessible thanks to this format,” Krefting says.

However, even though we know much about the ocean thanks to the ship’s logs, this has not prevented its degradation, according to the researchers.

“We have known a lot about how our activities are changing the ocean, especially biologically. But knowledge does not always help. The degradation of the ocean is the result of choices and politics,” says Krefting, and Paulsen adds:

“Our research shows that the ocean's problems are not solved simply by knowing more.”

Received no recognition

But what became of our dear General Mathiesen and his theory about ocean currents?

He finally gets his ocean current theory published in French. Unfortunately for him, he gains no traction for the theory, and thus no attention. Most likely, his disappointment is immense.

One day, however, a very positive review of his publication appears in the newspaper Aftenposten, signed by a certain
“Spectator”. There’s just one problem: the one who wrote the review is himself.

“He seems rather manic. We find not just one draft of the review, but many,” Paulsen recounts, adding:

“It may sound strange to be so interested in ocean currents, but actually it is one of the really big questions that we still have about the ocean.”

Moisture-damaged treasures

Mathiesen did not succeed in writing himself into the history of science, but all the work he put in is now a starting point for climate history.

“I am truly surprised by how important the logbooks have been. This applies both in the past and today. Perhaps we will extract entirely different things from them in the future,” says Paulsen.

Ellen Krefting finds it fascinating how our understanding of the ocean is linked to what she describes as piles of moisture-damaged papers with poor handwriting:

“Think about how important this paperwork has been and that it can still be used to find new knowledge. It is not a given that it would become such an important knowledge format.”

About the project

“Maritime Modernities: Formats of Oceanic Knowledge” is a project that examines the long lines in the history of knowledge about the ocean, from the 17th century to today.

The project looks at the history of how particular “knowledge formats” have enabled the collection and transportation of knowledge about the ocean over the past 400 years. How have ship’s logs, maps, and models shaped our understanding and use of the oceans?