This book has been edited from the manuscripts of the late Scottish economist, Duncan Black. Shortly after the publication of "The Theory of Committees and Elections", Black started to collect material for papers and a book on Lewis Carroll's theory of proportional representation. Black's chapter plans made it clear that the book was to be in three parts, written by himself, followed by a reprint of Carroll's "Principles of Parliamentary Representation" and its main sources. Part 1 is biographical, introducing Lewis Carroll and giving relevant details of his life. Part 2 is Black's already published work on Lewis Carroll. Part 3 comprises the more detailed arguments about Carroll's reasoning, and Part 4 contains reprints of rare original material on proportional representation by Carroll, James Garth Marshall and Walter Baily.