This coloured line engraving portrays the vessels Alexander, Isabella, Dorothea, and Trent, which formed part of the Polar Expedition of 1818. Above each portrait is inscribed the vessel's name, weight, number of crew members and the name of her captain. The Alexander was hired for the expedition under John Ross, who was sent out to try and find a North West passage from the Atlantic to the Pacific. Lieutenant W.E. Parry, who commanded the 'Alexander', was second in command of the expedition. Although described as a "hired brig" (see J.J. Colledge, "Ships of the Royal Navy : an historical index", 1908-1997), she is shown ship-rigged here and in the illustrations by John Ross of his account of the voyage.

Below the portraits of the four vessels, it is Inscribed: "Portraite of the Vessels on the Polar Expedition of 1818./ The projecting timbers are for hoisting up the Boats to: but in bad weather they are got on board and laid/ upon the cross pieces, bottom upward, from bow to stern. The projections are placed two between the/ fore and main masts, and one between the main and mizen, and one at the stern."

Plate 20.