The 18th century saw a resurgence of hope that a Northwest Passage - that elusive target of European seamen over the centuries - might yet be found. Prompted by the Irish MP Arthur Dobbs, the Admiralty sent the Furnace and Discovery to Hudson Bay in 1741 in search of a navigable passage to the Pacific. The expedition was commanded by Christopher Middleton, until his resignation in 1741 a sea captain in the service of the Hudson's Bay Company. With his actions closely scrutinized by his former employers and colleagues, concerned about possible interference with the fur trade, Middleton wintered at the Company fort at Churchill. From there in the summer of 1742 he sailed farther north along the west coast of Hudson Bay than any previous European explorer, charting Wager bay, Repulse Bay and Frozen Strait; but he failed to find a passage. After his return to England he found himself accused of negligence and corruption. Dobbs attacked both him and the Hudson's Bay Company in a campaign which ruined Middleton's professional reputation and opened the way for a further expedition to the Bay. The controversy over the Middleton expedition helps to explain the wealth of documentation which has survived. In angry pamphlet exchanges Dobbs and Middleton published their letters to each other; and to these the editors have added Dobb's manuscript Memorial on the Northwest Passage, his correspondence with Judge Ward, and documents from the Admiralty and other government departments. The voyage itself is seen through the pages of Middleton's journal, supplemented with extracts from the journals, logs and affidavits of other crew members. From the Hudson's Bay Company's archives the journal of James Isham, factor at Churchill, adds to the story of the expedition's wintering. The final section deals with the controversy which developed after Middleton's return, and prints the more important charges and counter-charges which were made in the years 1743 to 1745.