Day had broken cold and gray， exceedingly cold andgray， when the man turned aside from the main Yukontrail and climbed the high earth-bank， where a dim andlittle-travelled trail led eastward through the fat sprucetimberland. It was a steep bank， and he paused for breathat the top， excusing the act to himself by looking at hiswatch. It was nine o’clock. There was no sun nor hint ofsun， though there was not a cloud in the sky. It was a clearday， and yet there seemed an intangible pall over the face ofthings， a subtle gloom that made the day dark， and that wasdue to the absence of sun. This fact did not worry the man.
He was used to the lack of sun. It had been days since hehad seen the sun， and he knew that a few more days mustpass before that cheerful orb， due south， would just peepabove the sky-line and dip immediately from view.
The man flung a look back along the way he had come.
The Yukon lay a mile wide and hidden under three feet ofice. On top of this ice were as many feet of snow. It wasall pure white， rolling in gentle undulations where the icejamsof the freeze-up had formed. North and south， asfar as his eye could see， it was unbroken white， save for adark hair-line that curved and twisted from around thespruce-covered island to the south， and that curved andtwisted away into the north， where it disappeared behindanother spruce-covered island. This dark hair-line was thetrail—the main trail—that led south five hundred milesto the Chilcoot Pass， Dyea， and salt water； and that lednorth seventy miles to Dawson， and still on to the northa thousand miles to Nulato， and finally to St. Michael onBering Sea， a thousand miles and half a thousand more.
But all this—the mysterious， far-reaching hair-line trail，the absence of sun from the sky， the tremendous cold，and the strangeness and weirdness of it all—made noimpression on the man. It was not because he was longused to it. He was a newcomer in the land， a chechaquo，and this was his first winter. The trouble with him wasthat he was without imagination. He was quick and alertin the things of life， but only in the things， and not in thesignificances. Fifty degrees below zero meant eighty-odddegrees of frost. Such fact impressed him as being coldand uncomfortable， and that was all. It did not lead himto meditate upon his frailty as a creature of temperature，and upon man’s frailty in general， able only to live withincertain narrow limits of heat and cold； and from there onit did not lead him to the conjectural field of immortalityand man’s place in the universe. Fifty degrees belowzero stood for a bite of frost that hurt and that must beguarded against by the use of mittens， ear-flaps， warmmoccasins， and thick socks. Fifty degrees below zero wasto him just precisely fifty degrees below zero. That thereshould be anything more to it than that was a thought thatnever entered his head.
As he turned to go on， he spat speculatively. There wasa sharp， explosive crackle that startled him. He spat again.
And again， in the air， before it could fall to the snow，the spittle crackled. He knew that at fifty below spittlecrackled on the snow， but this spittle had crackled in theair. Undoubtedly it was colder than fifty below—howmuch colder he did not know. But the temperature did notmatter. He was bound for the old claim on the left forkof Henderson Creek， where the boys were already. Theyhad come over across the divide from the Indian Creekcountry， while he had come the roundabout way to takea look at the possibilities of getting out logs in the springfrom the islands in the Yukon. He would be in to camp bysix o’clock； a bit after dark， it was true， but the boys wouldbe there， a fire would be going， and a hot supper wouldbe ready. As for lunch， he pressed his hand against theprotruding bundle under his jacket. It was also under hisshirt， wrapped up in a handkerchief and lying against thenaked skin. It was the only way to keep the biscuits fromfreezing. He smiled agreeably to himself as he thought ofthose biscuits， each cut open and sopped in bacon grease，and each enclosing a generous slice of fried bacon.
He plunged in among the big spruce trees. The trailwas faint. A foot of snow had fallen since the last sledhad passed over， and he was glad he was without a sled，travelling light. In fact， he carried nothing but the lunchwrapped in the handkerchief. He was surprised， however，at the cold. It certainly was cold， he concluded， as herubbed his numb nose and cheek-bones with his mittenedhand. He was a warm-whiskered man， but the hair on hisface did not protect the high cheek-bones and the eagernose that thrust itself aggressively into the frosty air.
At the man’s heels trotted a dog， a big native husky， theproper wolf-dog， gray-coated and without any visible ortemperamental difference from its brother， the wild wolf.
The animal was depressed by the tremendous cold. Itknew that it was no time for travelling. Its instinct told it atruer tale than was told to the man by the man’s judgment.
In reality， it was not merely colder than fifty below zero；it was colder than sixty below， than seventy below. It wasseventy-five below zero. Since the freezing-point is thirtytwoabove zero， it meant that one hundred and sevendegrees of frost obtained. The dog did not know anythingabout thermometers. Possibly in its brain there was nosharp consciousness of a condition of very cold such aswas in the man’s brain. But the brute had its instinct. Itexperienced a vague but menacing apprehension thatsubdued it and made it slink along at the man’s heels， andthat made it question eagerly every unwonted movementof the man as if expecting him to go into camp or to seekshelter somewhere and build a fire. The dog had learnedfire， and it wanted fire， or else to burrow under the snowand cuddle its warmth away from the air.
The frozen moisture of its breathing had settled on itsfur in a fine powder of frost， and especially were its jowls，muzzle， and eyelashes whitened by its crystalled breath.