|PREFACE TO THE REVISED AND ENLARGED EDITION 1871
DIVISIONS OF THE SUBJECT
OF MATTER AND ITS PROPERTIES
MECHANICS, on THE LAWS OF MOTION
THE MECHANICAL POWERS
REGULATORS OF MOTION
GALVANISM, OR VOLTAIC ELECTRICITY
THE ELECTROMAGNETIC TELEGRAPH
THE ELECTROTYPE PROCESS
DIVISIONS OF THE SUBJECT
What is Natural Philosophy?
1. NATURAL PHILOSOPHY, or PHYSICS, is the science which treats of the powers, properties and mutual action of natural bodies, and the laws and operations of the material world.
2. Some of the principal branches of Natural Philosophy are
Mechanics, Electricity, Pneumatics, Galvanism, Hydrostatics. Magnetism, Hydraulics, Electro-Magnetism, Acoustics, Magneto-Electricity, Pyronomics, Astronomy, Optics,
NOTE. This list of branches might be considerably enlarged, but perhaps a rigid classification would rather suggest the omission of some of them, as pertaining to the department of chemistry.
What is Mechanics?
Mechanics is that branch of Natural Philosophy which relates to motion and the moving powers, their nature and laws, with their effects in machines.
4. Mechanics is generally considered under two divisions, called Statics and Dynamics.
5. The word Statics is derived from a Greek word implying test and it is applied to that department of mechanics which treats of the properties and laws of bodies at rest.
6. Dynamics, from a Greek word signifying power or force treat of the properties and laws of bodies in motion.
7. Pneumatics treats of the mechanical properties and effects or of aer and similar fluids, called elastic fluids or gases.
8. Hydrostatics treats of the gravity and pressure of fluids in a state of rest.
9. Hydraulics treats of fluids in motion, and of the instruments and machines by which their motion is guided or controlled.
10. Acoustics treats of the laws of sound.
11. Pyronomics treats of the laws and effects of heat.
12. Optics treats of light, color and vision.
13. Electricity treats of an exceedingly subtle agent, jailed the electric fluid.
14 Galvanism (sometimes called chemical Electricity) is a branch of Electricity.
15. Magnetism treats of the properties and effects of the magnet or loadstone.
16. Electro-Magnetism treats of magnetism induced by electricity.
17. Magneto-Electricity treats of electricity induced by magnetism.
18. Astronomy treats of the heavenly bodies, the sun, moon, stars, planets, comets.
19. The agents whose effects or operations are described in Natural Philosophy are divided into two classes, called respectively Ponderable and Imponderable Agents.
NOTE. Some writers on Philosophy have suggested a different classification, into Bodies and Agents, calling bodies ponderable, and agenta imponderable.
20. Ponderable agents are those which have weight, as water, air, steam.
21. Imponderable agents are those which have no weight such as light, heat, magnetism and electricity.