Seven-Tenths

by James Hamilton-Paterson

  It was as if Darwin’s intellectual leap had caused natural laws to rewrite themselves and the invisible ‘floors’, which until so recently had prevented sounding lines from reaching the deep ocean bed, all collapsed at once – like adamantine membranes – and began letting through an array of plummets, grabs, dredges, corers and other sampling devices. Now dredging expeditions began finding sea animals which resembled fossils. Specimens of a stalked crinoid, Rhizocrinus lofotensis, were brought up from the deep off Norway. No known modern coastal species of this sea lily had a stalk. This was followed by all kinds of hitherto unknown varieties of starfish and sponges from the world’s oceans and further reinforced the idea of ‘living fossils’ which would presumably be more and more archaic the further down they lived. Though completely wrong, this notion did at least give oceanography the last impetus it needed to begin the systematic exploration of the deep.

  Now that the problem was no longer conceptual, the major difficulty lay in designing equipment for taking deep soundings and samples. Where sounding was concerned, it was one thing to pay out a weight on the end of a line over the side of a ship but quite another to know when it had reached the bottom, since even the thinnest sounding wire weighed a lot with 2,000 fathoms deployed. Men became expert at judging when the plummet had stopped, keeping a sensitive finger on the line as it vanished overboard. However it was done, it was a laborious process. Thomson recorded that in 1868 aboard the Lightning a ‘Hydra’ sounder was used which, weighted with 336 pounds, took 33.5 minutes to reach 2,435 fathoms off Biscay and 2 hours and 2 minutes to heave back up again with a few ounces of grey Atlantic ooze. This system was much modified in detail but little changed until the invention of sonar depth-sounding. Even forty years after Thomson, the young Boyle Somerville aboard the Penguin was using a more or less identical process. ‘Birmingham Wire gauge no. 20, galvanised’ was paid out over a 9-inch diameter wheel from a huge drum holding about 6,000 fathoms. The little wheel was connected to a counter graduated in fathoms. There was a complex system of inertia brakes acting on the big spool, automatically gripping and releasing it according to the ship’s motions, thereby maintaining a safe and even tension in the wire. The weight on the end was called a ‘driver rod’, actually an iron tube, and was supplemented by two cone-shaped lumps of cast iron. Despite the brakes on the drum the entire process had to be watched ‘like a hawk’, and in fact they lost 10,000 fathoms (nearly 11.5 miles) of wire, two driver rods and two deep sea thermometers before they were successful. Then, ‘We were the first to see land that came from a depth below sea-level which was just a little more than the height of snow-topped Everest is above it.’* The Penguin’s skipper had been on the Challenger with Thomson and related a story which showed that where certain things were concerned, oceanographers had from the beginning had a sense of the priorities. At first, he remembered, the scientists had attached bottles of beer to their sounder in order to cool them. When they came up again from the icy depths the seals were intact and the corks still in place but the contents found to be ‘the very best seawater’. This method having failed, the beer was set to cool in the samples of ooze dredged up from 2,000 fathoms. This was very cold, about 35°F, and no scientific investigations were made of the sample until the beer had reached its optimum coolness.

  Pranks aside, that earlier expedition had marked the high point of nineteenth-century oceanography. At Christmas 1872 HMS Challenger had sailed from Portsmouth for what turned out to be a three and a half year voyage. At the time it was the best-equipped (at government expense) scientific expedition ever mounted. Some would argue it remains the greatest of all such voyages of discovery. One of the expedition’s specific hopes was to find ‘living fossils’, and the scientists aboard vainly sifted ton after ton of bottom samples in search of wriggling trilobites. What they did find was life in even the deepest parts of the ocean. The ‘azoic’ theory was by now officially dead, of course; yet it lingered on in vestigial form owing to the technical inadequacy of the sampling instruments of the day. That is, the expedition’s director, Charles Wyville Thomson, observed there was life both at the top and the bottom of the ocean for the simple reason that it was sustainable there. Even the deepest sediments were colonised by organisms such as worms, echinoderms and omnivorous crustaceans, so it was not surprising that abyssal and even hadal (the deepest of all; that is, over 6 kilometres) ecologies could also support highly specialised types of fish. Yet Wyville Thomson still felt sure that the oceans’ middle layer would turn out to be sterile because it lacked nutrients. Such particles as there were fell straight through it and down to the seabed. His problem lay in proving or disproving this. There was as yet no reliable way of taking samples from these intermediate zones without also catching specimens from the upper layer through which a net had to pass twice.

  During this long voyage there came a reminder of another enduring myth, and in sad circumstances. William Stokes, a young sailor aboard Challenger, was killed in an accident on deck. On the day of his burial at sea, a delegation of his shipmates approached Wyville Thomson and enquired anxiously whether their friend’s body, when suitably weighted, would truly reach the bottom or, as tradition had long maintained, would float at some indeterminate depth. Wyville Thomson was able to reassure them that his remains would indeed reach the bottom. A sounding taken shortly before Stokes’s funeral read nearly 4 miles, at that time the deepest ever measured.

  What would happen to the boy’s body on its long fall of over 21,000 feet? A 2-pound cannon ball would take well over half an hour to reach the bottom. A corpse, far less dense and streamlined, might take hours, assuming it was not attacked and dismembered on the way down. Just as it is impossible at any funeral entirely to suppress anxiety and not wonder, in however fleeting and censored a fashion, exactly what the worms or flames will shortly do, there must have been scientists on deck that day wondering about the effects of pressure on the late William Stokes. (It is most likely that a human body has never been retrieved from such a depth. Although corpses must have been subjected experimentally to enormous pressures to see what happens, the results are presumably buried in the files of naval research institutions.) Wyville Thomson had already written in musing manner: ‘At 2,000 fathoms a man would bear upon his body a weight equal to twenty locomotive engines, each with a long goods train loaded with pig iron.’* By now he had got his facts straight about the incompressibility of water.

  Any free air suspended in the water, or contained in any compressible tissue of an animal at 2,000 fathoms, would be reduced to a mere fraction of its bulk, but an organism supported through all its tissues on all sides, within and without, by incompressible fluids at the same pressure, would not necessarily be incommoded by it. We sometimes find when we get up in the morning, by a rise of an inch in the barometer, that nearly half a ton has been quietly piled upon us during the night, but we experience no inconvenience, rather a feeling of exhilaration and buoyancy, since it requires a little less exertion to move our bodies in the denser medium.†

  At some point the air-containing parts of Stokes’s body would have ruptured, principally those of his face, chest and abdomen. The head would not have burst because the cranium contains no air, only incompressible liquids, but the delicate bone honeycombs of his sinuses probably collapsed before water could leak in to equalise the pressure. Sooner or later the chest could have imploded, the broken ends of the ribs coming through the skin. Any air in the gut would probably rupture the abdomen, so if Stokes had been a flatulent boy it would in the end have been his literal undoing. The pressure would also have been likely to cause stress fracturing of certain parts of his skeleton. There might, for example, have been some splitting around the pelvic crest since the abdominal wall is highly compressible whereas the pelvis is not. The same would have applied generally to any structures of finely divided bone (i.e. not solid and thick as in the femur). Stokes would have arrived on the bottom somewhat smaller than he had been on the surface, especially
if he was fat, since fat is more compressible than water. The creatures of the seabed would make short work of his flesh, of course, once they had found their way through the holes his rib-ends had poked through the canvas; yet even his skeleton would not last as long as in a conventional earth burial since bone softens in seawater as its salts are leached out by osmosis. Thus softened, the boy’s remains would have crumbled away beneath the pressure.

  A vivid demonstration of what deep-sea pressure can do is shown in the experiment beloved by modern oceanographers of sending down with a piece of high-tech equipment an ordinary empty polystyrene coffee cup. It comes back in miniature, a tiny white thimble, all its insulating air cells having collapsed. Yet there seems to be a reluctance to perform this experiment with the body of an animal. I scoured the Farnella for a ship’s rat, hoping that if we could kill a brace we might send them down a couple of thousand fathoms to see what ruptured, but this piece of curiosity was greeted with cries of distaste and accusations of being a ghoul.

  In all, the Challenger covered 68,930 nautical miles and at the end of three and a half years brought back so many samples of marine plants, animals, seawater, sediment dredgings and corings that it took the next nineteen years to process them. By then Wyville Thomson was dead and his place had been taken by his assistant John Murray. The subsequent report, which by 1895 had reached fifty volumes, has been described as ‘the most complete expression of man’s knowledge of the deep sea’.* Perhaps as importantly, the enterprise encouraged similar expeditions by other nations, principally the USA, France, Germany, Russia, Italy and the Scandinavian countries. Even Monaco came to hold an honourable position in marine research since Prince Albert I was himself an expert yachtsman and oceanographer who financed his own expeditions. Among his most valuable contributions was a collection of specimens from the intermediate zone which Thomson had thought might be azoic.

  Part of the Challenger’s achievement was to have laid to rest various misconceptions and to have settled theoretical disputes. Prominent among the latter were post-Darwinian issues concerning living fossils and the Earth’s geological evolution. The short answer to the expectation that the deeps concealed living fossils was that they did not. What they revealed was absolute proof that even the greatest depths were neither immobile nor sterile, and that they supported species which, far from remaining unchanged for 60 million years or more, had evolved their own range of special adaptations.* In the mean time, other professional judgements were painfully exposed as incorrect. A few years before the Challenger expedition set sail Darwin’s friend and champion, T. H. Huxley, had formulated two hypotheses which became causes célèbres, one concerning a notional living fossil of the most primitive kind, the other geology.

  In June and July 1857 HM frigate Cyclops, while sounding down to 2,400 fathoms, brought up some sediment samples which in due course arrived back in London for examination. Huxley, at the time Palaeontologist at the London School of Mines, had them preserved in strong alcohol and appeared to forget about them until 1868. On re-examining them after eleven years he found a transparent jelly and became convinced that this was a living slime which carpeted the deep ocean floor, ingesting ooze and forming a rich layer of protoplasm which became a food supply for other life forms. As such, he gave it the name Bathybius haeckelii in honour of the German biologist Ernst Haeckel. Haeckel had been much struck by Darwin’s theories and was preoccupied with finding a primitive organism which might provide the missing link between inanimate matter and life. The catchphrase of the day was ‘abiogenesis’ or ‘spontaneous generation’, to describe the belief that living organisms could develop from non-living matter. (At a microbiological level this was exploded by Pasteur. In the present century an updated form of the idea was floated when amino acids, the ‘building blocks of life’, were generated in the laboratory by imitation lightning discharges in mixtures of gases thought to approximate Earth’s primordial atmosphere.) Haeckel was convinced Bathybius was the basis of all evolution, the original living matter or Urschleim. Whatever else, it would have to be a subject for investigation aboard Challenger since once Huxley had found and named it everybody else seemed to be dredging up samples and it was important to establish whether this primordial slime could be found evenly distributed throughout the world’s oceans.

  For two years Challenger found no Bathybius and finally the expedition’s chemist, John Buchanan, discovered that he could reproduce this jelly-like substance when he preserved bottom samples in alcohol. He came to the conclusion that this famous protoplasm was no more than calcium sulphate precipitated out of seawater by the alcohol. Thomson at once wrote to Huxley who promptly, and with immense dignity, admitted the correctness of this chemical explanation and his own error. From that moment Bathybius was dead, although several scientists tried in vain to discredit the explanation and its discoverer’s retraction.*

  The second of Huxley’s hypotheses also concerned deep-sea ooze, but in a geological rather than biological context. This was his theory of the ‘continuity of chalk’ which, briefly, stated that deep-sea ooze turned into the chalk deposits found on land, so that the continents were formed of the compacted material of the seabed. The essence of this position was the belief of the day that land could only move vertically up and down, for this was long before men like Emile Argand and Alfred Wegener had proposed lateral movement and continental drift. This gave rise to a debate between those scientists who believed the ocean basins and the high continents slowly traded places, and those who thought basins remained basins and continents continents. The Challenger soon put paid to the continuity of chalk theory, too. It found that deep-sea oozes were quite distinct chemically from rock formations on land. Besides, geologists had for years been turning up shallow-water fossils in chalk beds on land, showing they could never have been formed in the deep oceans. The upshot was that no evidence was found either for drowned continents or rising ocean basins. This was a particular disappointment to palaeontologists, zoologists, botanists and others who thought they needed a sunken land bridge to explain how they were finding close correspondences between species of animals and types of geological formation in otherwise widely separated land masses. They, too, had to wait for Wegener as well as for theories of convergent evolution which explained how unrelated organisms can evolve similar shapes and adaptations in response to similar environments.

  Behind this gathering of knowledge and the dispelling of misconception and superstition grew a desire to visit the deeps in person. In a way, the development of the submarine from the early twentieth century onwards was merely tantalising, since submarines were incapable of descending deeper than a few hundred feet, scarcely beyond the euphotic zone. Compared with reaching the deeps, this was the equivalent of getting a toe wet. Besides, submarines were war machines, not research vessels, and were far too big. They had the inherent problem of needing to support a large volume of air against great external pressure. This could only be achieved by massive construction, otherwise they would be crushed like a ribcage. Not until the 1930s did a true hero emerge prepared to put his trust in a piece of equipment which Alexander the Great would certainly have disdained.

  This was the bathysphere, a name coined by its American inventor, William Beebe. The concept was simplicity itself. A thick-walled steel sphere with a circular entry hatch and a tiny porthole would be lowered like a plummet over the side of a ship on the end of a cable. In effect, it was an eyeball on a string. It could do nothing of itself but carry man’s sight into unseen regions. Beebe’s accounts of those early dives are in a sense laconic, even though shot through with terrifying images of the physical forces involved. The bathysphere was once sent down empty on a test dive and when hauled up was much heavier than usual. As the first bolts of the hatch were loosened needle jets of water sprayed out, showing it was partly full and under great pressure. It was clear to everyone that at some point in the loosening process the entire hatch might blow off, yet Beebe and his companion Otis Barto
n went on unscrewing the nuts with spanners while standing as far to one side as they could. When it finally did blow the heavy steel plate missed them both by fractions of an inch, flew the length of the deck, humming, and dented a donkey winch. Both men eventually felt the technological problems had been mastered, however, and made a historic series of dives cramped for hours in the tiny space, taking it in turns to squint awkwardly out of the peephole and dictate via telephone what they saw, while a female colleague in the ship far above took it all down in shorthand. A photograph taken on deck of Beebe emerging from the bathysphere shows the physical toll these long dives took. He is barely able to get through the tiny hole, so stiff is he with cold and cramp. There is no clutter of emergency equipment on deck, no officious bustle of rescue teams dressed in special gear; just a thin man with a lined face wearing slacks and canvas shoes being helped out of a steel ball which looks not much bigger than a large mine. In 1934 he and Barton reached the record depth of 3,028 feet off Bermuda.