In 1887, the renowned German scientist Louis Lewin and his uncle, John Warburg, set out across the Atlantic on what was to be an arduous seven-week journey spanning the North American continent, east and west. Lewin's wife, Clara, remained in Berlin with their daughters. In daily letters, Lewin shares with Clara his account of his trans-Atlantic trip, and of his subsequent travels by rail and steamer to Montreal, across Canada to Vancouver, thence to San Francisco, and from California back...