The Voyage of HMS Challenger

When NASA came to name their fleet of space shuttles, they chose to honour five famous ships and a space craft used for scientific discovery in the past. The ill-fated Challenger was named after a pearl-class corvette launched in February 1858. After a relatively uneventful career in the Royal Navy, she was chosen for one of the most ambitious scientific expeditions of the age. She was sent out to explore and map the seafloor of the world’s oceans, an area of the planet as unknown then as deep space is today.

Until the mid-19th century only the shallower parts of the seas had been mapped and explored. The general assumption was that nothing could exist in the perpetual dark, chilling cold and crushing pressure of the deep ocean. But some contested this view. The biologist Thomas Huxley (known as Darwin’s Bulldog for his robust defence of the theory of evolution) in particular hoped that the origins of life would be discovered here. He had studied a mysterious substance called bathybius haeckelii from the seabed, that he believed to be a form of primordial life, halfway between living and organic matter.

The invention of the telegraph also prompted interest in the deep ocean. The new technology had revolutionised communications, accelerating the speed at which a message could be sent from the pace of a horse or steamship to being almost instantaneous. In 1866 the first successful trans-Atlantic cable was laid, connecting the telegraph systems of America and Britain. But this triumph had followed several costly andunsuccessful attempts. Telegraph companies were reluctant to lower their valuable equipment down into an unknown environment often miles beneath their ships. They were now demanding more information about the sea floor before they would invest in ambitious new under-sea cables to fully connect the continents of the world. When they had encountered problems during the laying of Atlantic cables and had raised them back to the surface, they were surprised to find the occasional deep-sea coral or strange creature attached to them. Could there be life in the abyss after all?

In the 1870s the decision was taken to send an expedition to explore the world’s oceans. It was a combined effort by the Royal Society, which would provide a team of eminent scientists, and the Royal Navy, which would supply a ship and crew. The scientists selected included a German, a Swiss and a Canadian and they covered every field including biology, geology, physics and chemistry. In addition, a second team was established to process data and samples at Edinburgh University. The task the mission was set showed typical Victorian ambition. They were to map the ocean floor of the world; study its geology and search for new life. They were also to study the chemistry and physics of the ocean itself, as well as the distribution of marine life throughout the globe.

HMS Challenger was a good choice of vessel. She had been built when the navy was in transition between sail and steam and was equipped with both. This meant she combined the ability of sail to stay at sea for long periods, and steam power to hold the ship stationary while plumbing the depths. She had also proved her reliability, having already circumnavigated the globe. She was extensively rebuilt to convert her into a research ship. Her magazine was converted to store a different hazardous material - the thousands of gallons of alcohol that would be required to preserve specimens. All but two of her guns were removed, replaced by a suite of well-equipped laboratories. These even included a dark room, allowing the work of the mission to be fully recorded. For example, the first ever photograph of an iceberg was taken from HMS Challenger.

The expedition set off in 1872 and did not return until 1876. They zig-zagged their way down the Atlantic to Antarctica, across to Australia, extensively surveyed the Pacific before returning home around Cape Horn. Each day they would take extensive soundings along with temperature readings and samples from throughout the water column. They would also deploy a dredge on the bottom to collect minerals as well as plants and animals. The sea floor was usually several miles beneath them, and sometimes even more. It was HMS Challenger that discovered the seven-mile-deep Marianas Trench in the Pacific. Their daily task was described by one participant as “…like hovering in a balloon above an unknown land hidden by clouds.”

There was huge global interest in the expedition, making it the Victorian equivalent of the Apollo missions. Whenever HMS Challenger entered port crowds gathered to greet her. She was visited by dignitaries including the Emperor of Japan and the King of Portugal. Unlike previous expeditions, she was able to share her work during her voyage. Reports, including illustrations of fresh discoveries, appeared in newspapers and scientific journals alike and were eagerly devoured. Whenever she reached port she sent back cases of samples, over 600 in total, to the team waiting in Edinburgh. This was only possible thanks to the greater global connectivity of the 1870s. The samples she unloaded in Sydney, Australia returned home via a new steamship service to San Francisco, (only just established the previous year), crossed the US on the brand-new transcontinental railway to New York, where they were loaded onto the regular Royal Mail steam packet for London.

The achievements and discoveries of the expedition were prodigious. They revealed that the deep ocean was rich in life, discovered thousands of new species, including some commercially valuable ones, such as the monkfish. They also discovered that the sea floor was littered with debris, including manganese nodules and cosmic dust that had accumulated over millions of years, perfectly preserved beneath the waves. Much of their observations are invaluable to modern day science, providing a wealth of data about the state of the oceans before climate-change really got underway. The fifty-volume Challenger report, which took 76 authors 15 years to complete is widely regarded as the foundation document of the science of oceanography.

As for HMS Challenger she didn’t return to active service. She was used as a training ship, then was a receiving hulk on the Medway for a while, before being broken up in 1921 for scrap.