Note: Concerning English-language works and library records, at least: Some translations and illustrations cover both parts 1 and 2, of which both appear in some publications and part 1 alone in other publications. At the same time, some library records cover two volumes as one publication while others cover only the 1st or 2nd of a two-volume publication. Some publication titles, and also some WorldCat library records, do not clearly indicate the scope. OCLC 17170819, entirely clear, covers two volumes as one "1872-1873" publication.