X CONTENTS. 



PAGE 



89. Expression for Kinetic Energy 80 



90. Twist Velocity acquired by an Impulsive Wrench 81 



91. Kinetic Energy acquired by an Impulsive Wrench 82 



92. Formula for a Free Body 82 



93. Lemma ........ 83 



94. Euler s Theorem . 83 



95. Co-ordinates in a Screw System 83 



96. The Reduced Wrench 84 



97. Co-ordinates of Impulsive and Instantaneous Screws .... 85 



CHAPTER VIII. 

 THE POTENTIAL. 



98. The Potential . . . . 87 



99. The Wrench evoked by Displacement 88 



100. Conjugate Screws of the Potential 89 



101. Principal Screws of the Potential 90 



102. Co-ordinates of the Wrench evoked by a Twist 91 



103. Form of the Potential 92 



CHAPTER IX. 

 HARMONIC SCREWS. 



104. Definition of an Harmonic Screw . 94 



105. Equations of Motion ........ 96 



106. Discussion of the Results 99 



107. Remark on Harmonic Screws 100 



CHAPTER X. 

 FREEDOM OF THE FIRST ORDER. 



108. Introduction 101 



109. Screw System of the First Order . . 101 



110. The Reciprocal Screw System 102 



111. Equilibrium 103 



112. Particular Case ..... 104 



113. Impulsive Forces 104 



114. Small Oscillations 105 



115. Property of Harmonic Screws 106 



