A quarter of an hour later from the deck Worsley saw the sun set a second time.

This strange phenomenon was due to mirage or refraction.

We attributed it to an ice-crack to the westward, where the band of open water had heated a stratum of air.
The drift of the pack was not constant, and during the succeeding days the crevassed berg alternately advanced and receded as the 'Endurance' moved with the floe.

On Sunday, April 18, it was only seven miles distant from the ship.
"It is a large berg, about three-quarters of a mile long on the side presented to us and probably well over 200 ft.high.

It is heavily crevassed, as though it once formed the serac portion of a glacier.