Sextant

by David Barrie

  To cross the Pacific Ocean, even under the most favorable circumstances, brings you for many days close to nature, and you realize the vastness of the sea. Slowly but surely the mark of my little ship’s course on the track-chart reached out on the ocean and across it, while at her utmost speed she marked with her keel still slowly the sea that carried her. On the forty-third day from land,—a long time to be at sea alone,—the sky being beautifully clear and the moon being “in distance” with the sun, I threw up my sextant for sights. I found from the result of three observations, after long wrestling with lunar tables, that her longitude by observation agreed within five miles of that by dead-reckoning.

  This was wonderful; both, however, might be in error, but somehow I felt confident that both were nearly true, and that in a few hours more I should see land; and so it happened, for then I made the island of Nukahiva, the southernmost of the Marquesas group,* clear-cut and lofty. The verified longitude when abreast was somewhere between the two reckonings; this was extraordinary.30

  Fig 9: Admiralty chart of Strait of Magellan, first published in the 1830s and based on surveys by King, FitzRoy and Stokes.

  Remarkable indeed, and very different from the result Slocum had obtained when he first performed the calculations. The first set of sights had put the Spray hundreds of miles west of her DR position, and Slocum knew that this could not be correct. So he took another set of observations with the utmost care, but the average result was about the same as that of the first set. He asked himself why, with his “boasted self-dependence,” he had not done better and, never lacking self-confidence, decided to look for a discrepancy in the tables. There he found that an important logarithm was in error:

  It was a matter I could prove beyond a doubt, and it made the difference as already stated. The tables being corrected, I sailed on with self-reliance unshaken, and with my tin clock fast asleep. The result of these observations naturally tickled my vanity, for I knew that it was something to stand on a great ship’s deck and with two assistants take lunar observations approximately near the truth. As one of the poorest of American sailors, I was proud of the little achievement alone on the sloop, even by chance though it may have been.31

  Slocum described how he was now in harmony with the world around him, as if carried on “a vast stream” where he “felt the buoyancy of His hand who made all the worlds”:

  I realized the mathematical truth of their motions, so well known that astronomers compile tables of their positions through the years and the days, and the minutes of a day, with such precision that one coming along even five years later may, by their aid, find the standard time of any given meridian on the earth. . . . The work of the lunarian, though seldom practiced in these days of chronometers, is beautifully edifying, and there is nothing in the realm of navigation that lifts one’s heart up more in adoration.32

  Errors in the tables on which navigators relied were rare, but they were not unknown, especially in the days when they depended on human calculators. In the late eighteenth century, the great Nathaniel Bowditch (1773–1838)—whose name is still attached to the standard American navigation manual—discovered numerous mistakes in John Hamilton Moore’s Practical Navigator. Although most were unimportant, the incorrect listing of the year 1800 as a leap year meant that the solar declination for March 1, 1800, was out by 22 minutes—an error that led to at least one shipwreck.33 Nevertheless, it says much not only for Slocum’s self-confidence, but also for his mathematical skills, that he was able to find the faulty logarithm in the tables he was using and then rectify it. A less experienced navigator might well have assumed that the mistake was his own and given up. It is also interesting that Slocum acknowledges the possibility that the accuracy of his lunar-based fix may just have been a fluke.

  Slocum crossed the Pacific by way of Samoa—where he visited the house of his hero Robert Louis Stevenson, who had only recently died there—and when he reached Australia discovered that he was “news.” He was now able to earn money by giving lectures to audiences keen to hear about his adventures. Slocum then headed north from Sydney and passed through the Torres Strait before calling at the Cocos Islands and Mauritius en route to South Africa. By the time he returned home in June 1898 he was a celebrity, and his account of the voyage (published in 1900) has since become a classic. His latter years were, however, darkened by a charge of rape brought against him in 1906 by a girl of twelve. He was let off with a reproof from the judge for his “great indiscretion” and banned from ever again visiting the town where the offense had occurred.34 Slocum disappeared at sea after setting sail from Martha’s Vineyard on a single-handed voyage to the Amazon in November 1908.

  Chapter 16

  Endurance

  Day 18: Fog and drizzle descend on us. But still doing 6½ knots until mid-morning. Slept for an hour or so and when I got up there was fog with visibility down to half a mile or less. Wind eased slightly slowing us to 5½ knots but even so, by noon we had covered 155 miles by the log. Our best day’s run. No sights but noon position by DR: 47°27' N, 20°21' W. Land’s End only 600 miles away.

  Talked with Colin about naval warfare and how Captain Cook conducted his surveys. The sextant was useful not just for celestial work but also for fixing positions by horizontal angles—triangulation.

  Saw another Portuguese man-of-war. A butterfly—a Large White I think—flapped by strongly. Where was it going? Where was it from?

  Played Salvoes with Alexa. Fog persisted in evening and we all felt tired and bored. Wind almost died and we trickled along at 3–4 knots. Good stew for supper with whisky and rice pudding.

  Day 19: A better breeze and making 4–5 knots on 090° under a NW wind force 2–3. The fog began to lift at 0730 and we managed to take some sights which I worked out and plotted. The position line strongly suggested that we’d gone south of our course by perhaps 5–10°.* Later in the day we took the spare compass up forward and confirmed that the steering compass was deviating by this amount to the south.

  A very calm day. Some sun finally broke through and I put on my shorts again. Then the wind dropped almost completely. A strong swell was running and, with the sails flogging uselessly, we rolled miserably for an hour or two before reluctantly starting up the motor. Once we were moving again, it was more comfortable as we no longer had to brace ourselves constantly to avoid being thrown around. Reading Erskine Childers’ Riddle of the Sands. Very jingoistic but good descriptions of small boat sailing. By now getting BBC radio loud and clear all day and heard news of Nixon’s resignation. Got time signal—chronometer behaving well though actually not much more accurate than my wristwatch. A very hot day at home it seems.

  Noon position 47°19' N, 17°23' W and 119 miles run. An enjoyable quiet sail but a test for our patience with England only 500 miles off now.

  The Atlantic gale we experienced in Saecwen was nothing compared to the storms that many sailors have had to endure—especially in the Southern Ocean, which encircles Antarctica. Here strong, often very strong, westerly winds blow almost without intermission throughout the year across thousands of miles of ocean, and enormous seas have time and space to build up. This was the scene in 1916 of an extraordinary epic of survival that illustrates the vital importance both of good seamanship and of the skill that comes from years of practice with a sextant.

  The hero of this story was Frank Worsley, a merchant seaman from New Zealand, who had, like Slocum before him, learned his trade under sail. In 1888, at the age of sixteen, Worsley joined a clipper ship sailing to England, a passage that gave him his first experience of a Southern Ocean gale. He described the “terrific grandeur of the scene and the danger of toppling seas rolling on, ridge behind ridge” as the ship headed toward the Diego Ramírez Islands:

  It is too late to heave-to; the ship might founder in the attempt. It is necessary to drive her to prevent her from pooping or broaching-to, and so the captain cracks on with four full sails and reefed mainsail and defying the gale, refuses to lo
wer the topsail.1

  Worsley rose steadily up the ladder and was given his first command in 1901, a trading schooner in which he travelled widely in the South Pacific. His experience of handling small boats among the islands was to prove invaluable later. He joined the Royal Naval Reserve and in due course settled in London, where, in 1914, he met Sir Ernest Shackleton. “The Boss,” as he was known to his crew, was planning a grand expedition to cross the Antarctic continent, and he was looking for someone to command the ship that was to take him there: the Endurance. His first choice had, perhaps presciently, turned the job down and Worsley was appointed almost by chance:

  One night I dreamed that Burlington Street was full of ice blocks, and that I was navigating a ship along it—an absurd dream. Sailors are superstitious, and when I woke up next morning I hurried like mad into my togs, and down Burlington Street I went. I dare say that it was only a coincidence, but as I walked along, reflecting that my dream had certainly been meaningless and uncomfortable and that it had cost me time that could have been used to better purpose, a sign on a door-post caught my eye. It bore the words “Imperial Trans-Antarctic Expedition,” and no sooner did I see it than I turned into the building with the conviction that it had some special significance for me.2

  Worsley and Shackleton met briefly. “The moment I set eyes on him,” Worsley later recalled, “I knew that he was a man with whom I should be proud to work,” and Shackleton must have taken a liking to Worsley because he hired him on the spot. In August 1914, just as World War I was breaking out, Worsley was ready to set sail. As a reservist, he, like many other members of the crew (twenty-eight men in all), expected to be called up, and Shackleton in fact put the ship at the disposal of the Royal Navy. However, word came down from the First Lord of the Admiralty, Winston Churchill, that the expedition should go ahead. Everyone believed that the war would soon be over.

  The Endurance reached Buenos Aires in October, where Shackleton joined her, and then called at South Georgia. Although there were alarming reports of the extent of the ice pack, the Endurance headed south on December 5 and was soon pounding her way through the ice floes.3 On January 19, 1915, their slow, zigzag progress finally ceased when the ship was only sixty miles from her planned destination on the Antarctic coast. Sextant observations placed her in 76°34' South, 31°30' West, and land was faintly visible in the east,4 but despite heroic efforts to free her, the Endurance was inextricably beset in pack ice. On January 22 they reached the southernmost point of their drift and the southern summer was over. The temperature was dropping, the sea was freezing solidly around them, and Shackleton “could not now doubt that the Endurance was confined for the winter”:

  We must wait for the spring, which may bring us better fortune. . . . My chief anxiety is the drift. Where will the vagrant winds and currents carry the ship during the long winter months that are ahead of us?5

  On February 24 they ceased to observe ship routine and the Endurance became a winter station, with the many sledge dogs kennelled in igloos on the ice. Seals provided fresh meat for dogs and men alike. The accommodation aboard the ship was adapted so that the crew could survive the winter in reasonable comfort. Although they kept themselves busy exercising the dogs, making scientific observations, and organizing games, the long months of drift must have been extraordinarily trying. On May 1, 1915, they said good-bye to the sun and Shackleton wrote in his journal:

  One feels our helplessness as the long winter night closes upon us. By this time, if fortune had smiled upon the Expedition, we would have been comfortably and securely established in a shore base. . . . Where will we make a landing now? . . . Time alone will tell.6

  Their position on May 2 was 75°23' South, 42°14' West—about 170 nautical miles from the nearest part of the Antarctic coast. An “Antarctic Derby” sledge race was held on June 15 and Midsummer’s Day (midwinter in the Antarctic) was celebrated with a big party.7 By now the ship was drifting steadily northward with the ice pack. A prolonged, severe storm in July led to the break-up of the ice around the ship on August 1.8 Floes forced their way beneath her keel and others crashed into her alarmingly. Shackleton readied the boats in case the crew needed quickly to abandon ship, but the Endurance survived this assault. A sextant sight of the star Canopus on August 3 confirmed their northward progress. Wonderful mirages appeared over the ice, as Shackleton recorded in his journal:

  The distant pack is thrown up into towering barrier-like cliffs, which are reflected in blue lakes and lanes of water at their base. Great white and golden cities of Oriental appearance at close intervals along these cliff tops indicate distant bergs, some not previously known to us. Floating above these are wavering violet and creamy lines of still more remote bergs and pack. The lines rise and fall, tremble, dissipate, and reappear in an endless transformation scene. The southern pack and bergs, catching the sun’s rays, are golden, but to the north the ice masses are purple. Here the bergs assume changing forms, first a castle, then a balloon just clear of the horizon, that changes swiftly into an immense mushroom, a mosque, or a cathedral.9

  In September the ship was again threatened by the surrounding ice, and at the end of the month, as “the roar of the pressure grew louder,” Shackleton could see an area of disturbance in the ice pack that was rapidly approaching:

  Stupendous forces were at work and the fields of firm ice around the Endurance were being diminished steadily. . . . The ship sustained terrific pressure on the port side forward. . . . It was the worst squeeze we had experienced. The decks shuddered and jumped, beams arched, and stanchions buckled and shook. I ordered all hands to stand by in readiness for whatever emergency might arise.10

  Worsley warmly praised the Endurance, whose behavior in the ice had been “magnificent”:

  She has been nipped with a million-ton pressure and risen nobly, falling clear of the water out on the ice. She has been thrown to and fro like a shuttlecock a dozen times. She has been strained, her beams arched upwards, by the fearful pressure; her very sides opened and closed again as she was actually bent and curved along her length, groaning like a living thing. It will be sad if such a brave little craft should be finally crushed in the remorseless, slowly strangling grip of the Weddell pack after ten months of the bravest and most gallant fight ever put up by a ship.11

  The ship stood firm, and warmer weather gave them hope that they might yet escape the grip of the ice. During October they survived further contests with the ice, but at the end of that month they were pinched between three different pressure ridges, and at last the Endurance began to leak heavily. Worsley had the vital task of clearing one of the pumps, frozen solid deep in the bilges:

  This is not a pleasant job. . . . We have to dig a hole down through the coal while the beams and timbers groan and crack all around us like pistol shots. The darkness is almost complete, and we mess about in the wet with half-frozen hands and try to prevent the coal from slipping back into the bilges. The men on deck pour buckets of boiling water from the galley down the pipe as we prod and hammer from below, and at last we get the pump clear, cover up the bilges to keep the coal out, and rush out on deck, very thankful to find ourselves safe again in the open air.12

  For the moment they could keep the leaks under control, but the end was approaching. On October 26 something very strange occurred, which to men in their situation must have seemed ominous. Eight emperor penguins suddenly appeared out of a crack in the ice, just as the pressures on the ship were reaching their destructive climax:

  They walked a little way towards us, halted, and after a few ordinary calls proceeded to utter weird cries that sounded like a dirge for the ship. None of us had ever before heard the emperors utter any other than the most simple calls or cries, and the effect of this concerted effort was almost startling.13

  The next day, Shackleton was finally forced to abandon ship. He found it hard to write what he felt:

  To a sailor his ship is more than a floating home, and in Endurance I had centred ambitio
ns, hopes and desires. Now, straining and groaning, her timbers cracking and her wounds gaping, she is slowly giving up her sentient life at the very outset of her career. She is crushed and abandoned after drifting more than 570 miles in a northwesterly direction during the 281 days since she became locked in the ice.14

  Now they could only watch helplessly as the Endurance was at last destroyed:

  The twisting, grinding floes were working their will at last on the ship. It was a sickening sensation to feel the decks breaking up under one’s feet, the great beams bending and then snapping with a noise like heavy gunfire. . . . The plans for abandoning the ship in case of emergency had been made well in advance, and men and dogs descended to the floe and made their way to the comparative safety of an unbroken portion of the floe without a hitch. Just before leaving, I looked down the engine room skylight as I stood on the quivering deck, and saw the engines dropping sideways as the stays and bed plates gave way. I cannot describe the impression of relentless destruction that was forced upon me as I looked down and around. The floes, with the force of millions of tons of moving ice behind them, were simply annihilating the ship.15

  They were in a tight spot, and it was not clear what they should do. Shackleton was in favor of dragging the ships’ boats over the ice to the nearest land, now some 350 miles distant, where he hoped to find a store of emergency supplies that he had left there some years earlier, but this preposterous plan soon proved impracticable. Morale was understandably low, and there was almost a mutiny, but Shackleton managed to maintain discipline. They now had no choice but to follow Worsley’s more sensible advice. This was to allow the ice to carry the whole party and all the equipment they had saved from the wreck as far north as possible and then take to the boats. Accordingly they settled down to endure five months encamped on the ice pack.