Part 2

Attraction of Gravitation, continued. Of Weight. Of the Fall of Bodies. Of the Resistance of the Air. Of the Ascent of Light Bodies.

CONVERSATION III.

ON THE LAWS OF MOTION. 32

Of Motion. Of the Inertia of Bodies. Of Force to produce Motion. Direction of Motion. Velocity, absolute and relative. Uniform Motion. Retarded Motion. Accelerated Motion. Velocity of Falling Bodies. Momentum. Action and Reaction equal. Elasticity of Bodies. Porosity of Bodies. Reflected Motion. Angles of Incidence and Reflection.

CONVERSATION IV.

ON COMPOUND MOTION. 46

Compound Motion, the result of two opposite forces. Of Curvilinear Motion, the result of two forces. Centre of Motion, the point at rest, while the other parts of the body move round it. Centre of Magnitude, the middle of a body. Centripetal Force, that which impels a body towards a fixed central point. Centrifugal Force, that which impels a body to fly from the centre. Fall of Bodies in a Parabola. Centre of Gravity, the point about which the parts balance each other.

CONVERSATION V.

ON THE MECHANICAL POWERS. 54

Of the Power of Machines. Of the Lever in general. Of the Lever of the first kind, having the Fulcrum between the power and the weight. Of the Lever of the second kind, having the Weight between the power and the fulcrum. Of the Lever of the third kind, having the Power between the fulcrum and the weight. Of the Pulley. Of the Wheel and Axle. Of the Inclined Plane. Of the Wedge. Of the Screw.

CONVERSATION VI.

ASTRONOMY.

CAUSES OF THE MOTION OF THE HEAVENLY BODIES. 70

Of the Earth's annual motion. Of the Planets, and their motion. Of the Diurnal motion of the Earth and Planets.

CONVERSATION VII.

ON THE PLANETS. 80

Of the Satellites and Moons. Gravity diminishes as the Square of the Distance. Of the Solar System. Of Comets. Constellations, signs of the Zodiac. Of Copernicus, Newton, &c.

CONVERSATION VIII.

ON THE EARTH. 91

Of the Terrestrial Globe. Of the Figure of the Earth. Of the Pendulum. Of the Variation of the Seasons, and of the Length of Days and Nights. Of the Causes of the Heat of Summer. Of Solar, Siderial, and Equal or Mean Time.

CONVERSATION IX.

ON THE MOON. 108

Of the Moon's Motion. Phases of the Moon. Eclipses of the Moon. Eclipses of Jupiter's Moons. Of Latitude and Longitude. Of the Transits of the inferior Planets. Of the Tides.

CONVERSATION X.

HYDROSTATICS.

ON THE MECHANICAL PROPERTIES OF FLUIDS. 118

Definition of a Fluid. Distinction between Fluids and Liquids. Of Non-Elastic Fluids, scarcely susceptible of Compression. Of the Cohesion of Fluids. Of their Gravitation. Of their Equilibrium. Of their Pressure. Of Specific Gravity. Of the Specific Gravity of Bodies heavier than Water. Of those of the same weight as Water. Of those lighter than Water. Of the Specific Gravity of Fluids.

CONVERSATION XI.