This is a book for the leisure hour, and contains a popular narrative of some of the famous impossibilities which have been attempted by those who have taken the name of science in vain, as well as a number of arithmetical puzzles, optical delusions and similar entertaining matter. The seven follies with which the author deals in the larger part of the book are "The Squaring of the Circle," "The Duplication of the Cube," "The Trisection of the Angle," "Perpetual Motion," "Alchemy," "The Fixation of Mercury" and "The Elixir of Life." A book of this kind does not call for serious criticism, and it would even be too much to expect that the author's explanations of why the perpetual motion absurdities cannot work should in every case be as ingenious as the absurdities themselves.