Then, too, there are on the polar ice those little patches of sapphire blue already mentioned, made from the water pools of the preceding summer.

On the Greenland ice-cap years ago I had been spurred on by the necessity of reaching the musk-oxen of Independence Bay before my supplies gave out.

Now I was spurred on by the necessity of making my goal, if possible, before the round face of the coming full moon should stir the tides with unrest and open a network of leads across our path.
After some hours the sledges caught up with me.

The dogs were so active that morning, after their day's rest, that I was frequently obliged to sit on a sledge for a few minutes or else run to keep up with them, which I did not care to do just yet.

Our course was nearly, as the crow flies, due north, across floe after floe, pressure ridge after pressure ridge, headed straight for some hummock or pinnacle of ice which I had lined in with my compass.
In this way we traveled for ten hours without stopping, covering, I felt sure, thirty miles, though, to be conservative, I called it twenty-five.
My Eskimos said that we had come as far as from the _Roosevelt_ to Porter Bay, which by our winter route scales thirty-five miles on the chart.