This volume, first in the Yale Research Series of Boswell's journals, covers his emotionally eventful travels as a young man through the German and Swiss territories. It begins in mid-June 1764 and ends on New Year's Day 1765, when he crossed the Alps for the next stages of his European tour in Italy, Corsica, and France. The volume includes the complete text of Boswell's diaries and memoranda, as well as a daily record of expenses and his frequently revealing "Ten Lines a Day" poems. This volume is the Research Series parallel to the 1953 trade series edition, Boswell on the Grand Tour: Germany and Switzerland, 1764, whose annotation the editor, Marlies K. Danziger, expands, supplements, and, in many instances, corrects.