A meter used to test batteries.

Ammeter

A meter used to test batteries.

"Galvanism is the branch of electric science to which an experiment by Galvani gave birth. His wife, who was making soup from frogs, put them in proximity to a charged electrical machine. On touching them with a scalpel their legs became greatly convulsed. He came to the erroneous conclusion that animal electricity existed in the nerves and muscles of frogs, etc. His contemporary Volta inferred that the metals took the active part in producing the contraction, and the electricity was due to their contact. In 1800 he first described and constructed what has since been called the Voltaic pile."—(Charles Leonard-Stuart, 1911)

Galvanic Battery

"Galvanism is the branch of electric science to which an experiment by Galvani gave birth. His wife,…

"In Bunsen's instrument a test tube is sealed into and enclosed by an outer tube, the lower part of which, together with a tube leading from it to a narrow gauge, is filled with mercury."—Finley, 1917

Bunsen's Calorimeter

"In Bunsen's instrument a test tube is sealed into and enclosed by an outer tube, the lower part of…

"Apparatus used for calorimetric experiments." —The Encyclopedia Britannica 1910

Calorimetric Apparatus

"Apparatus used for calorimetric experiments." —The Encyclopedia Britannica 1910

"If a piece of wire gauze is held over an unlighted gas jet, the gas may be lighted on either side (figure 6), but the flame will not pass through the meshes. The wires conduct the heat away so rapidly that the gas on the other side does not get hot enough to ignite. This id the principal of the safety lamp, used in coal mines where inflammable gases collect. The lamp flame is surrounded by a wire gauze, and thus kept from igniting the dangerous gases outside." Louis Derr, 1911

Two Gas Jets Beneath Wire Gauze wiPower Generation, Steamth a Lit Flame

"If a piece of wire gauze is held over an unlighted gas jet, the gas may be lighted on either side (figure…

An example of converting mechanical energy to heat.

Energy Conversion

An example of converting mechanical energy to heat.

An illustration showing the interchangeability of heat and mechanical energy.

Heat Conversion

An illustration showing the interchangeability of heat and mechanical energy.

"Machine used to generate electricity by induction using transformed kinetic energy from the crank." -Avery 1895

Induction Machine

"Machine used to generate electricity by induction using transformed kinetic energy from the crank."…

"In mechanics, the word 'machine' signifies an instrument for the conversion of motion or the transference of energy." -Avery 1895

Man Using Lever and Fulcrum to Lift Rock

"In mechanics, the word 'machine' signifies an instrument for the conversion of motion or the transference…

"When the pendulum hands at rest in a vertical position, as Pa, it has no energy at all. Considered as a mass of matter seperate from the earth; it certainly has potential energy; but considered as a pendulum, it has not." — Avery, 1895

Path of a pendulum

"When the pendulum hands at rest in a vertical position, as Pa, it has no energy at all. Considered…

A device used for demonstrating the elastic properties of materials.

Physics demonstration

A device used for demonstrating the elastic properties of materials.

"If a pair of concave mirrors be set facing each other, as shown in figure 7, and a source of heat be placed in the focus of one, a thermometer in the focus of the other will quickly show a rise in temperature though the mirrors are many feet apart." Louis Derr, 1911

A Pair of Concave Mirrors Set Facing Each Other

"If a pair of concave mirrors be set facing each other, as shown in figure 7, and a source of heat be…

"Irregular reflection or diffusion results from the incidence of radiant energy upon an irregular surface, as is illustrated. Bodies are made visible to the eye mainly by the light that they thus diffuse." -Avery 1895

Irregular Reflection or Diffusion

"Irregular reflection or diffusion results from the incidence of radiant energy upon an irregular surface,…

"Regular reflection results from the incidence of radiant energy upon a polished surface. When a beam of light falls upon a mirror, the greater part of it is reflected in a definite direction as is illustrated, and forms an image of the object from which it came. A perfect mirror would be invisible." -Avery 1895

Regular Reflection

"Regular reflection results from the incidence of radiant energy upon a polished surface. When a beam…

"When radiant energy passes through a medium bounded by parallel planes, the refractions at the two surfaces are equal and contrary in direction. The direction after passing through the plate is parallel to the direction before entereing the plate; the rays merely suffer lateral aberration." -Avery 1895

Refraction by Plates

"When radiant energy passes through a medium bounded by parallel planes, the refractions at the two…

This furnace is used to purify a gold concentrate. The gold concentrates, if non-pyritic, are treated in grinding pans in the bottom of which mercury is placed. The amalgam (mercury alloy), after squeezing out the excess mercury, is heated in the retort, to distil (separate) off the rest and leave the gold, which is then melted and cast into bars of gold bullion of varying fineness.

Retort Furnace for Gold Bullion

This furnace is used to purify a gold concentrate. The gold concentrates, if non-pyritic, are treated…

A long, spiral spring.

Spring

A long, spiral spring.

A steam engine is a heat engine that performs mechanical work using steam as its working fluid. Steam engines have a long history, going back almost two thousand years. Early devices were not practical power producers, but more advanced designs became a major source of mechanical power during the industrial revolution. Modern steam turbines generate about half of the electric power in the world.

Steam Engine

A steam engine is a heat engine that performs mechanical work using steam as its working fluid. Steam…

"The steam engine, in its many forms, is the agent by means of which part of th eenrgy stored up in the steam, as supplied by a coiler, is converted into mechanical or useful work."—Finley, 1917

Steam engines

"The steam engine, in its many forms, is the agent by means of which part of th eenrgy stored up in…

A wheel used to create energy by running water.

Water Wheel

A wheel used to create energy by running water.

A wheel used to create energy by running water.

Water Wheel

A wheel used to create energy by running water.

"Instrument designed to measure both the rate at which the electrical energy is delivered and the time that it is delivered, i.e., the number of watt-hours." -Avery 1895

Wattmeter

"Instrument designed to measure both the rate at which the electrical energy is delivered and the time…

A windmill is a machine that is powered by the energy of the wind. It is designed to convert the energy of the wind into more useful forms using rotating blades or sails. The term also refers to the structure it is commonly built on. In much of Europe, windmills served originally to grind grain, though later applications included pumping water and, more recently, generation of electricity.

Windmill

A windmill is a machine that is powered by the energy of the wind. It is designed to convert the energy…

A windmill is a machine that is powered by the energy of the wind. It is designed to convert the energy of the wind into more useful forms using rotating blades or sails. The term also refers to the structure it is commonly built on. In much of Europe, windmills served originally to grind grain, though later applications included pumping water and, more recently, generation of electricity.

Windmill

A windmill is a machine that is powered by the energy of the wind. It is designed to convert the energy…