BOOK I.. ~chap. 1.~ _of the Laws of Motion_

~CHAP. 1.~ Of the laws of motion The first law of motion proved p. 29 The second law of motion proved p. 29 The third law of motion proved p. 31

~CHAP. 2.~ Further proofs of the laws of motion The effects of percussion p. 49 The perpendicular descent of bodies p. 55 The oblique descent of bodies in a straight line p. 57 The curvilinear descent of bodies p. 58 The perpendicular ascent of bodies ibid. The oblique ascent of bodies p. 59 The power of gravity proportional to the quantity of matter in each body p. 60 The centre of gravity of bodies p. 62 The mechanical powers p. 69 The lever p. 71 The wheel and axis p. 77 The pulley p. 80 The wedge p. 83 The screw ibid. The inclined plain p. 84 The pendulum p. 86 Vibrating in a circle ibid. Vibrating in a cycloid p. 91 The line of swiftest descent p. 93 The centre of oscillation p. 94 Experiments upon the percussion of bodies made by pendulums p. 98 The centre of percussion p. 100 The motion of projectiles p. 102 The description of the conic sections p. 106 The difference between absolute and relative motion, as also between absolute and relative time p. 112

~CHAP. 3.~ Of centripetal forces p. 117

~CHAP. 4.~ Of the resistance of fluids p. 143 Bodies are resisted in the duplicate proportion of their velocities p. 147 Of elastic fluids and their resistance p. 149 How fluids may be rendered elastic p. 150 The degree of resistance in regard to the proportion between the density of the body and of the fluid In rare and uncompressed fluids p. 153 In compressed fluids p. 155 The degree of resistance as it depends upon the figure of bodies In rare and uncompressed fluids p. 155 In compressed fluids p. 158