CONTENTS. IX 



PAGE 



53. The Angle between Two Screws 48 



54. The Triangle of Twists 49 



55. Decomposition of Twists and Wrenches ....... 50 



56. Composition of Twists and Wrenches 50 



57. Screw Co-ordinates 51 



58. Reciprocal Screws ....... .... 51 



59. Another Representation of the Pitch 52 



60. Pitches of Reciprocal Screws ......... 53 



61. The Virtual Coefficient 54 



62. Another Investigation of the Virtual Coefficient 55 



63. Application of Screw Co-ordinates 57 



64. Properties of the Virtual Coefficient 59 



65. Another Construction for the Pitch 59 



66. Screws of Zero Pitch 60 



67. A Special Case 60 



68. A Tangential Section of the Cylindroid 60 



CHAPTER VI. 

 THE EQUILIBRIUM OF A RIGID BODY. 



69. A Screw System 62 



70. Constraints ............ 63 



71. Screw Reciprocal to a System 63 



72. The Reciprocal Screw System 63 



73. Equilibrium 64 



74. Reaction of Constraints 64 



75. Parameters of a Screw System 65 



76. Applications of Co-ordinates 65 



77. Remark on Systems of Linear Equations 67 



CHAPTER VII. 

 THE PRINCIPAL SCREWS OF INERTIA. 



78. Introduction 69 



79. Screws of Reference 70 



80. Impulsive Screws and Instantaneous Screws 71 



81. Conjugate Screws of Inertia - . . . . 71 



82. The Determination of the Impulsive Screw 72 



83. System of Conjugate Screws of Inertia 72 



84. Principal Screws of Inertia . 73 



85. An Algebraical Lemma 75 



86. Another Investigation of the Principal Screws of Inertia .... 76 



87. Enumeration of Constants 78 



88. Kinetic Energy ........ 79 



