Here is a fascinating study by L. Sprague de Camp of controversial and often little-known happenings in science and technology, with an emphasis on the wayward activities of those who dabble in fringe science. The Fringe of the Unknown is in three parts. The first, "Our Ingenious Forebears," examines some of the mysteries and oddities surrounding ancient technologies. Occultists and pseudoscientists often attribute extraordinary knowledge and wisdom to "the ancients," crediting them with inventions and discoveries that have generally been accepted as accomplishments of recent centuries. De Camp refutes some of these claims, but goes on to show that the ancients, starting from a much lower base of general knowledge, nevertheless achieved some remarkably ingenious results. In Part 2, "Beasts of Now and Then," the author explores a number of oddities and controversies in biology, such as the curious adventures and ramifications of the elephant family, the never-ending efforts to prove that monsters from former eras still roam the earth, the celebrated sighting of a sea serpent by H.M.S. Daedalus in the South Atlantic in 1848, and the many speculations about the great waves of extinction that have, from era to era, impoverished the earth's faunas. In Part 3, "Scientists, Mad and Otherwise," de Camp tells of the behavior of some scientists, from the merely eccentric to the certifiably insane, and examines the differences between real science and pseudoscience. This wide-ranging work is a treasury of entertaining accounts of history and science.