THESE problems are simple numerical exercises, mostly of an elementary character, on hydrostatics, “tenacity and elasticity,” statics and dynamics (including gravitation and pendulums), light, sound, heat, expansion of gases, magnetism and electricity. Such a collection of questions should be of much use for class-room exercises. The best way of learning the fundamental principles of elementary physics is undoubtedly to practise making numerical calculations with them, and the large number of questions will enable the book to be used with different classes. Many of the questions could almost be used as oral exercises.