CONTENTS. XVII 



CHAPTER XXIV. 



THE THEORY OF SCREW-CHAINS. 



CHAPTER XXV. 

 THE THEORY OF PERMANENT SCREWS. 



360. Introduction .... 399 



361. Different Properties of a Principal Axis ....... 400 



362. A Property of the Kinetic Energy of a System 401 



363. The Identical Equation in Screw-chain Co-ordinates 403 



364. The Converse Theorem 404 



365. Transformation of the Vanishing Emanant ....... 405 



366. The General Equations of Motion with Screw-chain Co-ordinates . . 405 



367. Generalization of the Eulerian Equations ....... 406 



368. The Restraining Wrench-chain 407 



369. Physical meaning of the Vanishing Emanant 408 



370. A Displacement without change of Energy ...... 408 



371. The Accelerating Screw-chain . 409 



372. Another Proof 409 



373. Accelerating Screw-chain and Instantaneous Screw-chain .... 410 



374. Permanent Screw-chains 410 



375. Conditions of a Permanent Screw-chain . . . . . . . 411 



376. Another identical Equation 412 



