Introductory Note 1 I Squaring the Circle 9 II The Duplication of the Cube 30 III The Trisection of an Angle 33 IV Perpetual Motion 36 V The Transmutation of Metals--Alchemy 79 VI The Fixation of Mercury 92 VII The Universal Medicine and the Elixir of Life 95 ADDITIONAL FOLLIES Perpetual or Ever-burning Lamps 100 The Alkahest or Universal Solvent 104 Palingenesy 106 The Powder of Sympathy 111 A SMALL BUDGET OF PARADOXES, ILLUSIONS, AND MARVELS (WITH APOLOGIES TO PROFESSOR DE MORGAN) The Fourth Dimension 117 How a Space may be apparently Enlarged by merely changing its Shape 126 Can a Man Lift Himself by the Straps of his Boots? 128 How a Spider Lifted a Snake 130 How the Shadow may be made to move backward on the Sun-dial 133 How a Watch may be used as a Compass 134 Micrography or Minute Writing. Writing so fine that the whole Bible, if written in characters of the same size, might be inscribed twenty-two times on a square inch 136 Illusions of the Senses 149 Taste and Smell 150 Sense of Heat 150 Sense of Hearing 150 Sense of Touch--One Thing Appearing as Two 151 How Objects may be apparently Seen through a Hole in the Hand 156 How to See (apparently) through a Solid Brick 158 CURIOUS ARITHMETICAL PROBLEMS The Chess-board Problem 163 The Nail Problem 164 A Question of Population 165 How to Become a Millionaire 166 The Actual Cost and Present Value of the First Folio Shakespeare 168 Arithmetical Puzzles 170 Archimedes and His Fulcrum 171 THE SEVEN FOLLIES OF SCIENCE