The Sir James Clark Ross Letter to Sir John Ross About the Ross Expedition to Antarctica is a letter from James to his uncle John, also an Arctic explorer. The letter was originally mailed to John with some gold pins that he had asked James to take to the farthest Southern latitude on ice he could reach, and then return; the pins were not present with the letter when it was received by the Byrd Polar and Climate Research Center Archival Program. It also details how James had left a silver case on the ice at that latitude, per his uncle's request. While the letter is undated, based on knowledge of when James had reached the Southernmost latitude on the expedition it dates to sometime between 1841 and 1844.