The spring of 1852 found him much broken in health. He had a wearing cough, and it was thought that his lungs were diseased. He waited only the termination of his assault and battery case in March, to start on a journey to the South with his father-in-law, Mr. Grinnell. The trip included a cruise to Bermuda and the West Indies, a short stay in Charleston, Savannah, and New Orleans, a visit to the Mammoth Cave, and a sojourn at the neighboring watering-place of Harrodsburg Springs. His letters to the “Home Journal” from these and other points in the South were reissued in book form as “A Health Trip to the Tropics.” During the years covered by this chapter he published a number of volumes similarly made up of periodical correspondence and miscellaneous contributions to his paper. “Rural Letters” contained his “Invalid Letters from Germany;” a reprint of “Letters from under a Bridge,” with two additional to those in the earlier editions; “Open Air Musings in the City;” letters from Sharon Springs and Trenton Falls in the summer of 1848; and one story, “A Plain Man’s Love.” “Hurrygraphs” comprised a series of letters from Plymouth, New Bedford, Cape Cod, and places on the Delaware and Hudson rivers; besides sketches--often very acute pieces of mental portraiture--of public men, authors, and other celebrities, and a good deal of chit-chat about society, the opera, etc., from the columns of the “Home Journal.” All that can be said of these traveler’s letters is that they are fairly good reporting. They hardly attain the rank of literature, and were as a whole not worth putting between covers. But Willis sold well and, therefore, found his account in continued book-making, bringing out, usually, simultaneous editions in London and New York. It is instructive to compare his letters from Cape Cod--a journey on which Mr. Grinnell was again his companion--with Thoreau’s book on the same piece of geography. Both men had quick eyes, and had taught themselves the art of observation. But Willis’s letters were the notes of an “amateur casual,” or “here-and-thereian,” on a flying trip over a sand-spit inhabited by queer people, who was always on the lookout for points which would interest the lady readers of a metropolitan journal. Thoreau, on the contrary, was like a palmer on a solemn pilgrimage to one of nature’s peculiar shrines, with loins girt up and staff in hand, tramping along the heavy sands, with the eternal thunder of “The Reverend Poluphloisboio Thalasses” in his ear; in serious and vigilant mood, watching every least token of the ways of the sea, but careless of men and reading publics.