A tin pocket flask from the 1845 British Northwest Passage Expedition led by Sir John Franklin. The flask is made from sheet iron, tinned and soldered (the joint is on the back). It is slightly flattened to fit into a pocket. The cap is missing.

The pocket flask was found at the boat site in Erebus Bay by Captain F. L. McClintock's sledge team on 30 May 1859, as part of the search expedition led by McClintock The site had been visited and partially investigated by Lt. William Hobson on 24 May but his report does not list everything he saw or removed. McClintock records ’a tin water bottle for the pocket'. [McClintock, Voyage of the Fox (1859), page 366].

The flask was displayed at the Royal Naval Museum, Greenwich, Case 2, No. 9. 'Tin water-bottle'. The item is shown in - 'Stereoscopic slides of the relics of Sir John Franklin's Expedition' photographed by Lieutenant Cheyne RN, at the United Services Museum, Whitehall, No. 6 (bottom right corner).