CONTENTS. 



PRELIMINARY REMARKS AND DEFINITIONS 1 



STATICS. 



Uniform Motion ... ; 13 



Forces and the Quantity of Motion ; . . 16 



Equilibrium between Forces directly opposite . . .18 



Compound Motion ..... 20 



Composition and Decomposition of Forces . . .25 



Moments and their Use in the Composition and Decomposition 



of Forces ...... 31 



Parallel Forces which act in different Planes . . .39 



Forces, the Directions of which are neither in the same Plane 



nor parallel to each other .... 41 



Centre of Gravity . . . . . .44 



Application of the Principles of the Centre of Gravity to par- 

 ticular Problems . . . . , 51 



Properties of the Centre of Gravity . . . .70 



General Principle of the Equilibrium of Bodies , . 76 



D'Alembert's Principle, and Concluding Deductions . . 77 



Application of the Principles of Equilibrium to the Machines 



usually denominated Mechanical Powers . . 80 



Rope Machine . . . . . .80 



Lever . .... 91 



Pulley . . . . . . .103 



Wheel and Axle . . . . . .109 



Inclined Plane . . . . .117 



Screw ....... 125 



Wedge ....... 129 



General Law of Equilibrium in Machines . . 131 



