Adventurous Fellows: Part One

While we may be stuck at home, join our Curator of Artefacts Glenn Benson over the next few weeks, as we follow some 'Adventurous Fellows' from the Society's history.

Published on 22nd May 2020

Deep Sea Observations on the Challenger Expedition

Sir Charles Wyville Thomson
Sir Charles Wyville Thomson

Sir Charles Wyville Thomson FLS. Stipple engraving by C. H. Jeens, 1876. Wellcome Collection (CC BY 4.0)

It struck me as strangely poignant that during the COVID-19 lockdown, while we are all required to stay in our own homes as much as possible, I was due to give a talk at the Linnean Society about some of its many ‘Adventurous Fellows’ and their extensive travels.

The limits imposed in the UK on how far you may travel to shop and to exercise has been a challenge for many of us, but it has also encouraged us to explore our local environment, perhaps more than we normally would. With quieter cities, and time on our hands, many of us have become aware of the natural history that is around us. Though aimed at children, Linnaeus at Home (our free-to-download activity book: has inspirational ideas for all ages in order to explore, record and learn about life on earth, and on our door step.

One of the greatest, arguably the greatest, adventure ever undertaken by any Fellow of the Society was by Sir Charles Wyville Thomson (1830–82), who led the civilian scientific team on board the HMS Challenger, on what was to become known as the Challenger Expedition (1872–76).

‘Thick as a family bible’

One of the many questions the expedition set out to answer was ‘how deep is the ocean’? Or, as I like to think of it, ‘how low can you go on Earth’? Thomson wrote:

The objects of the Expedition have been fully and faithfully carried out. We always kept in view that to explore the conditions of the deep sea was the primary object of our mission, and throughout the voyage we took every possible opportunity of making a deep-sea observation.

Track of the HMS Challenger

Map displaying the HMS Challenger's tracking and measurement of ocean surface density. Expedition Wikipedia Project

London’s Royal Society acquired the Challenger from the Royal Navy, removing her guns and making her fit for purpose by incorporating new laboratories and increasing the number of cabins. Between leaving Sheerness on 7 December 1872 and arriving at Spithead on 24 May 1876, the Challenger Expedition covered some 68,890 nautical-miles (127,580 km) measuring the depths of the oceans, and in the process, discovering and describing over 4,000 new species.

Examining a haul on the Challenger

The crew of the Challenger examines a haul as it is pulled on board. WikiMedia Commons/BL

Between 1886–95, around 100 scientists were involved in examining the findings and discoveries that were made. A series of reports on the expedition were written, and these ultimately filled 50 volumes that were each said to be as ‘thick as a family bible’. Overseeing their production fell, in the main, to (Sir) John Murray (1841–1914). The reports’ authors were not paid, though they were each given a copy of their published report and expenses. Murray spear-headed, and funded, the creation of a medal awarded to those who had contributed to the expedition and the subsequent work on its findings. The medals were designed by William S. Black (an Edinburgh artist active in 1881–97), and William Birnie Rhind, (1853–1933) an Edinburgh sculptor. They were cast, possibly in Paris, for the company James Crichton & Co., of 47 George Street, Edinburgh, Scotland. The Linnean Society holds one of the 120 bronze medals that were awarded from the Challenger Expedition offices in Queen Street, Edinburgh, between August 1895 and February 1897.

Challenger Medal

Challenger Medal awarded to Percy Sladen FLS, held in the Society's collections. The Linnean Society of London

This medal was presented to marine biologist Walter Percy Sladen FLS (1849–1900), for his work on the Asteroidea (Starfish) found during the expedition, a task that took him nearly a decade to complete. Sladen was Zoological Secretary (1875–85) and Vice President of the Society. (The Linnean Society administers the Percy Sladen Memorial Fund, making grants to support field work in the earth and life sciences:

So, just how low can you go on Earth?

The answer is to the bottom of the ‘Challenger Deep’—an oceanic trench named in the expedition’s honour, forming part of the Mariana (or Marianas) Trench in the western Pacific Ocean. In 1875, the scientists aboard the Challenger measured the depth of the deepest part of the trench to be 4,475 fathoms (8,184 m) deep. Modern-day measurements have put the depth at just over 10,900 m.

Was it the greatest adventure of any Fellow so far? If the facts already detailed are not sufficient to support my claim, I submit this as further evidence…

Two of the greatest technological explorations of modern times were named after the expedition: NASA’s ill-fated Space Shuttle Challenger, and the Apollo 17 lunar landing module (LM Challenger), the latter perhaps one of the greatest achievements of human kind.

Modern Challengers

(Left) A replica of the Space Shuttle Challenger, and (Right) Astronaut Harrison H. Schmidt stands in front of the Lunar Module Challenger on the Apollo 17 mission. Both were named after the Challenger Expedition of the 1870s. (LM Challenger image courtesy NASA)

‘Challenger Medals’ continue to be issued biennially by the Challenger Society for Marine Science. The modern-day medal is awarded to a UK marine scientist or person who has made a single major or sustained contribution to the development of marine science, or whose innovation has opened up new perspectives.


Stein, G. M. The Challenger Medal Roll.

Gardiner, B.G. (Ed.) 2003. ‘A biography of Percy Sladen (1849–1900)’, by Nichols, D., The Linnean Special Issue, No. 4

The Challenger Society for Marine Science:

‘Space Shuttle Overview: Challenger (OV-099)’, NASA :

Adventurous Fellows: Part Two
The Only Way Was Essex