"Plenty. Both the firemen on Number Six have went out from gas--in the snowshed. We've picked up a guy out of an ice gang that's willin' to stand th' gaff, but we need another one. Guess there ain't nothin' to do but wake up one of th' day crew. Hate t' do it, though--they're all in." "Don't, then. I'll make a try at it." "Know anything about firin' an engine?" "I know enough to shovel coal--and I've got a strong pair of shoulders." "Come on, then." Houston followed the figure toward the snowshed on the hill. Ten minutes later he stood beside a great Mallet engine, a sleek, glistening grayhound of the mountains, taking from the superintendent the instructions that would enable him to assist, at least, in the propulsion of the motive power. At the narrow areaway between the track and the high wall of the straightaway drifts through which the plow had cut, four men were lifting a limp figure, to carry it to the cars. The superintendent growled. "You payin' attention to me--or that guy they're cartin' off? When you get in them gas pockets, stick your nose in the hollow of your elbow and keep it there 'till you've got your breath again. There ain't no fresh air in that there shed; the minute these engines get inside and start throwin' on the juice, it fills up with smoke. That's what gets you. Hold your nose in your arm while you take your breath. Then, if you've got to shovel, keep your mouth and your lungs shut. Got me?" "Yes, sir." "Then go to it. Hey, Andy!" "Yeh." A voice had come from the engine cab. "Here's a guy that'll swing a shovel. I've told him about the gas." Barry climbed to his place on the engine. A whistle sounded, to be echoed and reechoed by the answering blasts of the snowplow train--four engines and the big auger itself--ready now for a fresh sally into the shed. Headlights, extinguished momentarily, were thrown on again, lighting up the dirty, ragged edges of the snow walls, with their black marks of engine soot; throwing into sharp relief the smudge-faced figures of the pick-and-axe crews just emerging from the black maw of the tunnel; playing upon the smooth, white outlines of the forbidding mountains yet beyond, mountains which still must be conquered ere the top of the world was reached. Ahead came the "high-ball" signal from the plow; two sharp blasts, to be repeated by the first, the second, the third and fourth of the engines. Then, throttles open, fire boxes throwing their red, spluttering glare against the black sky as firemen leaped to their task, the great mass of machinery moved forward.