The effect was repeated in an exaggerated form on the following day, when the ice-cliffs were thrown up above the horizon in double and treble parallel lines, some inverted.

The mirage was due probably to lanes of open water near the land.

The water would be about 30ｰ warmer than the air and would cause warmed strata to ascend.
A sounding gave 606 fathoms, with a bottom of glacial mud.

Six days later, on the 24th, the depth was 419 fathoms.

We were drifting steadily, and the constant movement, coupled with the appearance of lanes near the land, convinced me that we must stay by the ship till she got clear.