" One week!" she echoed. " One week of-us." I leaned forward and kissed her lips. " It will have to do for a lifetime."
Her voice was unsteady. " Sailhardy thinks the same?"
" No. He secretly cherishes a hope that one day he will make a greater open boat voyage than Shackleton, or even
Bligh of the Bounty. That blinds him. The sea is his friend, never forget, not his enemy. Forty-five miles to Thompson
Island is nothing to him."
" Except that it is not forty-five miles and there is no Thompson Island where the chart says," she said. She faced me. " Bruce, why, why, are you doing this thing? Why not take him to Thompson Island? Let him have it, even if it sends him completely… completely… unstable. .. when he finds that his caesium and all the rest of it is a dream."
" It is not a dream," I said.
" It… is… not… a… dream? I heard myself what you said to him about the caesium! Myself!"
" It is because I believe that there is caesium on Thompson Island that I am telling you this," I said slowly. " Thompson Island must never be found-never! You know what caesium means to our present-day world. A full-scale atomic war could be fought over Thompson Island."
" So you are prepared to sacrifice your own life and the lives of five other people?"
" Yes," I said. " Unless I can persuade your father when we are nearing the end of our tether to give ourselves up to Thorshammer-if we can find her." I began: " Thompson Island lies…"
She held her hand, now gloved again, over my mouth. "
Bruce, my darling, are you sure you want to tell me this? Quite, quite sure?"
" It is an act of faith," I replied. " Thompson Island lies sixty-five miles to the south-south-east of Bouvet."
It was minutes before she replied, and her voice was so soft I could scarcely hear the words. " Now I can ask how you alone know this."
"If you look on the vernier scale of my sextant-that is, the scale that's used for reading the angle of the sun and the stars-you'll see there is a little notch clearly filed. That is the latitude of Thompson Island. No one has ever searched for it there."
"But why…?"
" During the war I made what I considered a major discovery about the Antarctic. Light rays bend greatly in the Antarctic's cold air. You get refractions. You cannot take an accurate sighting."
" I don't understand-what are you trying to say?"
" The peculiar quality of light rays bending makes the positions of distant objects greatly distorted. In other words, the sextant lies. It puts the sun and the stars, on which we rely for navigation, out of position. I discovered that there is a consistent error of one hundred and ten miles too far north. Therefore instead of being forty-five miles to the northnorth-east of Bouvet, it is sixty-five miles to the south-south-east.
"
She wrinkled up her eyes in a puzzled way which brought to my eyes all the loveliness that had lain dormant for so long.
" I don't understand the logistics of what you're saying, although I accept it, Bruce. But what I can't understand is why, when everyone was wrong, including Norris when he first fixed the position of Thompson Island, that error should not have remained constant-in other words, even if it was marked at such and such a position and strictly it was wrong, why couldn't everyone else, making the same error because of light refractions, get there all the same?"
" The same thought struck me," I said. " Your assumption is that an old-time sealer was capable of getting an accurate fix, and that Bouvet's position itself was known."
" Bouvet itself?"
" I drew a map superimposing the various positions where Bouvet has been plotted," I replied. " There are at least four from reliable sources, and three from less reliable. To say that Thompson lies forty-five miles north-north-east of Bouvet doesn't mean a thing. In fact, I found on checking that the man who discovered Bouvet, the Frenchman Captain Bouvet de Lozier, first was supposed to have sighted land somewhere near where Norris said Thompson lies."
She laughed. " I'll bet you shot Bouvet's position down in flames too!"
I grinned back. " Yes, I did. You see, Bouvet based his longitude on the Cape Verde Islands, not on
Greenwich." 176
" I told you so!" she said delightedly. " But what about the oldtime sealers you were starting to tell me about?" I caught her mood. " Two important things: I spent months checking and rechecking logs and sealers' sighting reports in the Southern Ocean among old Wetherby's records. Briefly, it was nothing for a sealer to be out ten minutes in latitude under the most favourable conditions of weather, sun and stars. Their longitude really had them beaten, though. Don't forget, even during the Napoleonic wars, the only British warships which carried chronometers-essential for determining longitude-were the commanders of convoys. It was only four years after Napoleon's death that Norris found Thompson Island. After months of research, I found one could more or less rely on any old whaler being out about a degree and a half in longitude-say, ninety miles."
" What I can't understand is why you didn't tell the Admiralty all this when you were pressing your point about having seen Thompson Island."
I shrugged. " I was laughed practically out of the Admiralty down the Horse Guards Parade," I said. " I could see it in their faces-crackpot! Prove it, they kept on saying. It was just that opportunity I was asking for. One gentleman in the Hydrographic Department told me pointedly that it would throw every map ever made of the Southern Ocean and Antarctic into the wastepaper basket, and such waste could not be afforded. I remember his words stilclass="underline" ' Empiricism versus absolute knowledge, Captain Wetherby. We prefer absolute knowledge '."
" It may sound silly, but how did you arrive at the true position of Thompson Island, when your sextant lied, along with all other sextants?"
" By taking four different sextant sightings of the stars not the sun-to balance the refraction errors four ways." I said. " Norris was not…"
" Bruce!" she interrupted quickly. " Bruce! Look!" She pointed up the incline to where the slope resumed beyond the barrier of ice. Leaning over was the unmistakable snakelike head of a sea-leopard. Unless there was some way round and down, however, we were in no immediate danger.
" We must get back to the roverhullet and warn them," I said. The massive head and shoulders swayed backwards and forwards as if seeking some way down.
Suddenly, from high above towards the summit of the glacier, a white object detached itself.
I thought at first it was a chunk of ice. " Look, Helen. There's something diving down on the sea-leopard!"
It was a giant bird, his neck outstretched. He plummeted down like a Stuka dive-bomber. He could not be making for the sea-leopard, I told myself quickly-there must be some other prey we could not see on the ledge where the animal stood.
" Albatross!" exclaimed Helen.
The diving bird was upon the sea-leopard. He ballooned his wings to avoid hitting the snakelike head, but it was too late. We saw a flash of light as a claw lashed out. There was a burst of white feathers, and the white warpaint of the albatross was stripped down to the red flesh underneath. I could almost see the effort of the bird's neck muscles as he tried to lift himself. He would have made it, except for a projecting saw-edge of cliff. Wounded, he could not pull himself clear. He crashed into the glacier ice and came tumbling down in an untidy heap among the rocks at our feet.
Helen started to run towards the albatross, which rose up to a crouching position. He craned his fine neck and tried to rise. Across his left wing was a long tear from the sealeopard's claws. Bruce, we must help him…" she began, but she stopped at the look in my face and the ice-axe in my hand.
" No," I said gently. " No, Helen. Five minutes ago he was an adventurer who could have flown from here to the South Pole and back. Now he is a heap of feathers." I moved forward to administer the coup de grace. " He'll die slowly if we leave him, but quickly and mercifully if I do it. He must die, either way."