We stopped for lunch at the "lead" igloos, and as we finished our meal the ice opened behind us.

We had crossed just in time.

Here we noticed some fox tracks that had just been made.
The animal was probably disturbed by our approach.

These are the most northerly animal tracks ever seen.
Inspirited by our good fortune, we pressed on again, completing two marches, and when we camped were very near the 87th parallel.

The entry that I made in my diary that night is perhaps worth quoting: "Hope to reach the Marvin return igloo to-morrow.