See Introduction to the sketchbook and comment to folio 12 (D06631). This and folio 18 (D06637) depict larger ships in more severely frozen conditions, apparently with icebergs, than the other frost scenes in the book, and may represent an imaginative response to the Thames freeze of January 1814. Another possibility, perhaps suggesting an earlier date, is that they are related to Turner’s thoughts on the death of the explorer Hugh Willoughby, in verses – ‘Willoughby in frozen regions died’ – written in his Greenwich sketchbook (Tate D06721–D06829; D40666–D40668; Turner Bequest CII); Turner’s use of the two books overlapped. Willoughby took part in the ill-fated attempt to find a North-East Passage to China and India for the Company of Merchant Adventurers in 1553. Lacking any nautical or navigational experience and having become separated from the other two ships in a storm, he died trapped in ice at the mouth of the River Arzina on the coast near Murmansk. His remains were found the following year by Russian fishermen.