PAGE Introductory 5 The Mathematical Principle of the Slide Rule 6 Notation by Powers of 10 8 The Mechanical Principle of the Slide Rule 9 The Primitive Slide Rule 10 The Modern Slide Rule 12 The Notation of the Slide Rule 14 The Cursor or Runner 17 Multiplication 19 Division 24 The Use of the Upper Scales for Multiplication and Division 26 Reciprocals 27 Continued Multiplication and Division 28 Multiplication and Division with the Slide Inverted 30 Proportion 31 General Hints on the Elementary Uses of the Slide Rule 36 Squares and Square Roots 37 Cubes and Cube Roots 40 Miscellaneous Powers and Roots 45 Power and Roots by Logarithms 45 Other Methods of Obtaining Powers and Roots 47 Combined Operations 49 Hints on Evaluating Expressions 52 Gauge Points 53 Examples in Technical Calculations 56 Trigonometrical Application 74 Slide Rules with Log-log Scales 84 Special Types of Slide Rules 92 Long-Scale Slide Rules 96 Circular Calculators 101 Slide Rules for Special Calculations 109 Construction Improvements in Slide Rules 110 The Accuracy of Slide Rule Results 111 Appendix:— New Slide Rules 113 The Solution of Algebraic Equations 122 Screw-Cutting Gear Calculations 124 Gauge Points and Signs on Slide Rules 126 Tables and Data 128 Slide Rule Data Slips 133 THE SLIDE RULE.