For two decades, an international readership of workers in applied mathematics submitted their favourite puzzles to a mid-twentieth-century column, The Graham Dial. This original collection features 100 of the publication's very best problems, with themes ranging from logic and engineering situations to number theory and geometry. Each problem was specifically selected for its widely differing modes of solution, and most include several methods of solution plus assessments of their efficacy.In checking their solutions against the book's, readers may find that their interest in the puzzles increases. The search for an answer can develop into a challenge to improve upon existing solutions, as in a friendly competition among dozens of keen-witted, problem-solving engineers and mathematical puzzle fans. More than two dozen ""mathematical nursery rhymes"" appear throughout the book, which concludes with a final section of 25 ""quickies"" that will test readers' speed.