Speak up, jolly blade, never fear;

thirty miles behind. It was infuriating beyond measure to know that he was almost certainly within two or three hours' driving time from where we were, but without a wireless or any other means of contacting him he might as well have been a thousand miles away for any hope there was of two tiny moving objects encountering each other by chance in that vast and featureless land. Soon after eight o'clock in the morning I stopped to have a look at the two sick people on the sledge, professional instinct, I suppose, but an empty token gesture: there was nothing we could do for them, except give massage at frequent intervals. The sound of Mahler's dyspnoea, his whooping gasping breathing, was the tolling of a death-bell to our ears, and this effort to breathe was extinguishing the last embers of life in his emaciated and frozen body. In three hours' time, by noon at the latest, Mahler would be dead. Nothing could ever save him now, it was madness, an utterly wasted effort to continue to drag him along on a sledge: he was past caring or knowing or feeling now, he could die just as peacefully if we left him lying on the glacier. Or so I have thought since then. But Mahler was more than a man to us that day, he was a symbol: we would leave Mahler when he had drawn his last gasping breath, but never before. Marie LeGarde was dying too, but quietly, softly, peacefully, like a little candle flame flickering to extinction. Maybe she would go first, maybe Mahler. But both of them would die this day. The going was becoming increasingly difficult now, not so much because of the gradually steepening slope of the glacier which made the sledge overrun us more and more frequently, but because of the fact that Jackstraw's torch had all but completely given out, and the fissures and crevasses that, earlier, had merely been nuisances to be negotiated, now became menaces to be avoided at the cost of our lives. It was now that Balto proved of his greatest value yet: as Jackstraw had said on our first day out from the IGY cabin, the big Siberian had an uncanny nose for crevasses, both open and hidden, in daytime or dark, and he made never a mistake that morning, constantly running ahead and then back towards us to guide us in the safest direction. Even so, progress was heartbreakingly slow. Shortly after half-past eight in the morning we came across the tractor sled lying at an angle against a moraine. Even in the near darkness it was plain to see what had happened. The steepness of the glacier, not to mention sudden unaccountable dips to left and digital point and shot camera case right across its width, must have made the heavy sled a dangerous liability, for, from its tracks, we had several times seen where it had slewed wildly at an angle, pivoting round on its iron tow-bar as, brakeless, it had sought to overrun the tractor. Obviously, Smallwood and Corazzini must have fearedand with reason -that on one of these occasions it would pull round the tail of the tractor after it and topple the tractor on its side, or, worse, drag it into a crevasse: so they had unhooked the tow-bar and left the sled. It was surprising that they hadn't done this earlier: apart from carrying their fuel and food, which reserves could easily have gone into the tractor cabin itself, it had been a useless encumbrance to them. As far as I could judge they had abandoned it with all its contents-apart, of course, from the portable radio-including the wraps we had given Zagero and Levin when they had ridden on it at the point of a gun. We took these, tucked them round Mahler and Marie LeGarde and passed on. Three hundred yards later I stopped so abruptly, that the sledge, bumping into me, made me lose my footing on the slippery ice. I stood up, laughing softly, laughing for the first time for days, and Zagero came up close and peered into my face. "What gives, Doc?" I laughed again and was just on the point of speaking when his hand struck me sharply across the face. "Cut it out, Doc." His voice was harsh. "That ain't goin' to help us any." "On the contrary, it's going to help us a very great deal." I rubbed a hand across my cheek, I couldn't blame him for what he had done. "My God, and I almost missed it!" "Missed what?" He still wasn't sure that I wasn't hysterical. "Come on back to the tractor sled and see. Smallwood claims he thinks of everything, but he's missed out at last. He's made his first big mistake, but oh, brother, what a mistake! And the weather's just perfect for it!" I turned on my heel and actually ran up the glacier towards the sled. Many items were carried as standard equipment in ICY parties, both in the field and at base camps, and none more standard than the magnesium flares which first came into common use in the Antarctic over a quarter of a century agothey are indispensable as location beacons in the long polar nightsand radiosondes. We carried more radio-sondes than any other item of equipment, for