ed; it is
injurious to the human body. But our course was straight north. Dr.
Brende showed it to me on his chart--north, following the 70th West
Meridian. Compass corrections as we got further north--and astronomical
readings, these would take us direct to the Pole. I could never fathom
this air navigation; I flew by tower lights, and landmarks--but to Dr.
Brende and Georg, the mathematics of it were simple.

At two o'clock we had crossed the route of the Chicago-Great London Mail
flyer. But we did not see the vessel. The temperature was growing
steadily colder. The pit was inclosed, and I switched on the heaters.
Elza had fallen asleep on the side couch, with my promise to awaken her
at the first sign of dawn.

At two-thirty, the Greater New York-East Indian Express overhauled us
and passed overhead. It was flying almost north, bound for Bombay and
Ceylon via Novaya Zemlya. It was in the 18,000-foot lane. The air up
there was clear, but beneath us a fog obscured the land.

At intervals all this time Dr. Brende had been trying to raise
Robins--but there was still no answer. We did not discuss what might be
the trouble. Of what use could such talk be?

But it perturbed us, for imagination can picture almost anything. Georg
even felt the strain of it, for he said almost gruffly:

"Stop it, father. I don't think you should call attention to us so much.
Get the meteorological reports from the Pole--we need them. If they tell
us this weather will hold at 10,000 and below, we'll make good time."

Soon after three o'clock we swept over Hudson Strait into Baffinland. We
were down to 4,000 feet, but the fog still lay under us like a blanket.
It clung low; we were well above it, in a cloudless night, with no wind
save the rush of our forward flight.

Then came the pink flush of dawn. True to my promise I awakened Elza.
But there was nothing for her to see; the stars growing pale, pink
spreading into orange, and then the sun. But the fog under us still lay
thick.

We were holding our speed very nearly at 380 an hour. By daylight--about
five o'clock, after a light meal--we were over Baffin Bay. I had
relieved Georg at the controls. The headlands of North Greenland lay
before us. Then the fog lifted a little, broke away in places. The water
became visible--drift and slush-ice of the Spring, with lines of open
water here and there.

And then the fog closed down again, lifting momentarily at six o'clock
when we passed over