A History of Light and Lighting

Edition: 2.3 - (2005)

Copyright (c) 1990-2005 by Bill Williams

IN THE BEGINNING - (c 4.5 Billion BC)

Let There Be Light!

In the beginning it was dark and cold. There was no sun, no light, no earth, no solar system. There was nothing, just the empty void of space. Then slowly, about 4.5 billion years ago, a swirling nebula, - a huge cloud of gas and dust was formed. Eventually this cloud contracted and grew into a central molten mass that became our sun. At first the sun was a molten glow. As the core pressure increased, and the temperature rose to millions of degrees - a star was born. Through the process of thermonuclear hydrogen fusion, the sun began to shine.

This was the nebular hypothesis, first proposed in 1755 by the great German philosopher, Immanuel Kant.

THE SUN - (c 4 Billion BC)

Our sun is an atomic furnace that turns mass into energy. Every second it converts over 657 million tons of hydrogen into 653 tons of helium. The missing 4 million tons of mass are discharged into space as energy. The earth receives only about one two-billionths of this. Scientists calculate that the sun should keep burning for another 10 to 30 billion years. It has been estimated that in 15 minutes our sun radiates as much energy as mankind consumes in all forms, during an entire year.

The sun is approximately 93,000,000 miles from the earth, 864,000 miles in diameter, and is only an 'average' star in size, brilliance and age. There are more than 100 billion other stars in our sun's own galaxy, the Milky Way. Energy, with a color temperature of approximately 6500 degrees Kelvin, is received on earth, from the sun. It takes light from the sun approximately 8 minutes to reach the earth. The illumination on the earth's surface by the sun may exceed 100,000 lux, (10,000 fc) in mid summer.

THE EARTH - (c 4 Billion BC)

About 4 billion years ago, soon after the Sun was formed, the Earth and our other planets were formed from violent explosions and spinoffs from the process that created the Sun. The nine planets created are now known as Mercury, Venus, Earth, Mars, Jupiter, Saturn, Uranus, Neptune and Pluto, (arranged in order, from the sun). As rocks and other particles collided forming the Earth, it became molten. The rocks liquefied and the heavier elements sank to the core of the planet. The surface of the Earth cooled and hardened. Gradually oceans appeared and sunlight and water gave birth to life, eventually, intelligent life.

The earth has a diameter of 7,900 miles (compared to the sun's diameter of 864,000 miles).

EARLY LIFE - (c 3 Billion BC)

Without light, there would be no life. Life was dependent on three things being present: a.) the basic long molecule building block, carbon, b.) water, and c.) light. The Earth had all three. Eventually the oceans formed a rich organic soup that ultimately bore life. The oldest verified evidence of life comes from Rhodesia, where rocks formed approximately 3 billion years ago, bear 'stromatolites', the fossilized remains of algae.

Originally our atmosphere contained; hydrogen, helium, nitrogen, methane, ammonia and water vapor. For millions of years, the waste product of oxygen, from the ocean's algae, bubbled up out of the sea and into the atmosphere. Gaseous oxygen reacted strongly with the methane and ammonia in the atmosphere, turning it into carbon dioxide and water vapor. Over time, methane, ammonia and carbon dioxide were almost eliminated from the atmosphere. As oxygen began to build up in the atmosphere, the usual oxygen module (0-2) began to absorb ultraviolet wavelengths from the sun to form three atom molecules (0-3). In time a layer of poisonous ozone had built up high in the atmosphere, about 30 miles above the surface of the Earth. This ozone layer effectively blocked much of the damaging ultraviolet rays from reaching the Earth. Paleontological records show that life moved from the sea to land, only after the ozone layer had formed, providing a 'sunscreen' to protect the land from harmful ultraviolet radiation.

Today, the air we breath today is approximately 78 percent nitrogen, 20 percent oxygen and 2 percent noble gases, carbon dioxide and water vapor.

PHOTOSYNTHESIS - (c 2 Billion BC)

Somehow, as the primitive ocean organisms developed, one managed to develop a molecule that could use the energy of sunlight to produce food for itself. Sunlight, water, carbon dioxide and simple inorganic elements were all that was needed to sustain itself. No longer did ocean creatures have to eat other ocean creatures to survive. This was the birth of the first 'autotroph', a creature that could manufacture its own food. The plant was born and the process of photosynthesis had begun.

FIRST MAN - HOMO ERECTUS EMERGES - (c 1 Million BC)

EARLY MAN - (c 500,000 BC)

For people that lived before the dawn of history, there was no such thing as a solar system. The world as they understood it, was a small patch of land bounded perhaps by hills and by the blue line of the sea. Overhead was the sky, and across it rode the sun, a god, giving light and warmth. The moon was a lesser god, shining with a lesser light, and with it at night, rode the brilliant innumerable stars. Outside of this little universe, lay unimagined mystery.

FIRE, FLAME and TORCH - (c 400,000 BC)

Homo erectus probably discovered fire by accident. Fire was most likely given to man as a 'gift from the heavens' when a bolt of lightning struck a tree or a bush, suddenly starting it on fire.

The flaming touch and the campfire probably constituted early man's first use of 'artificial' lighting. For the first time man gained some small degree of freedom from the blindness of night, and some small degree of safety from the fear of unseen prowling beasts. As early as 400,000 BC, fire was kindled in the caves of Peking man.

The torch was the first portable lamp. One of the earliest developments was the discovery that a bundle of sticks tied together made a blazing torch, producing a brighter and longer lasting light. Man had finally learned to control fire and the human race was on the road to civilization.

The discovery of fire has had such a profound effect on humankind that all early societies constructed a myth to commemorate it. Years later, to the ancient Greeks, the fire bringer was Prometheus.

ANCIENT ART - (c 28,000 BC)

In the Ice Age snow and cold of 30,000 years ago, Cro-Magnon artists used natural pigments to create primitive paintings. Excellent examples of early art have been found in the cave at Lascaux, in France. Clearly man must have been using fire to provide the necessary light to create his art, as many painting have been found deep within caves, far beyond the reach of daylight.

PRIMITIVE LAMPS - (c 13,000 BC)

Prehistoric man, used primitive lamps to illuminate his cave. These lamps, made from naturally occurring materials, such as rocks, shells, horns and stones, were filled with grease and had a fiber wick. Lamps typically used animal or vegetable fats as fuel. Hundreds of these lamps (hollow worked stones) have been found in the famous Lascaux caves (France), dating to about 15,000 years ago.

The Sumerians of 2600 BC left behind them alabaster lamps so close to shell form that it is indisputable that shells themselves must have been used long before. Early man also realized that a crude reflector would help direct and intensify the light. Niches have been found carved into cave walls that are thought to have served this purpose.

In the Mediterranean area, hand fabricated lamps appear in Palestine, before 2000 BC.

Additional Reading: Greek and Roman Pottery Lamps, Donald Bailey, British Museum, 1972.

WORLD POPULATION - (8000 BC) - 100,000 people.

AGRICULTURE - (c 8000 BC)

About ten thousand years ago, man made an incredible discovery. For hundreds of thousands of years before, man has been a hunter/gatherer. Once man realized that he could actually plant crops and harvest them at specific times he now had a stable food supply. Man had discovered agriculture and now was able to settle down and farm a small patch of land. The knowledgeable use of light and other important factors brought man new freedom.

Successful agriculture meant for the most part predicting the seasons. Whoever could predict the coming of spring, the flooding of fertile river planes and the proper time to harvest - was certainly a god or a magician. It is possible that many ancient monuments were built to predict the coming of the seasons. The [STONEHENGE] is an example.

ANIMAL LAMPS - (c 5000 BC)

Animals were also used as lamps. Oily birds and fish needed only be threaded with a wick to produce a working lamp.

There are also records of the early use of fireflies to provide man with a source of convenient light. In the West Indian Islands (and also in Japan) fireflies were imprisoned in primitive cages to provide illumination through the process of bioluminescence. See also: [BIOLUMINESCENCE].

(REF: Lighting 1, Early Oil Lamps, British Science Museum, 1966).

EARLY LAMP FUELS - (c 5000 BC)

The fuel used in ancient lamps, depended largely on availability. Olive oil was probably the principal fuel employed in the Mediterranean countries, and was exported to areas where the olive did not grow. Other oils which were probable used in lamps include sesame oil (mainly in the East), nut oil, fish oil, castor oil and other plant oils.

Lamp fuels were editable, so lamps were more likely to be used by the wealthy than the poor. In times of hunger, fats would be consumed by the poor, and they would have less fuel available for their lamps.

(REF: Greek & Roman Pottery Lamps, Donald Bailey, British Museum,1972).

WORLD POPULATION - (3000 BC) - 100 million people.

EARLY LIGHTING - (3000 BC)

In the ancient civilizations of Babylonian and Egypt, light was a luxury. The Arabian Nights were far from the brilliance of today. The palaces of the wealthy were lighted only by flickering flames of simple oil lamps. These were usually in the form of small open bowls with a lip or spout to hold the wick. Animal fats, fish oils or vegetable oils (palm and olive) furnished the fuels.

ORIGIN OF THEATRE - (c 3000 BC)

Ancient theatre is as old as man's need to tell stories. The origins of theatre go far back into the past, to the religious rites of the earliest civilizations. Throughout the history of mankind there can be found traces of songs and dances in honor of a god, performed by priests and worshipers. The earliest civilization in which primitive rituals developed into truly elaborate performances was the Egyptian. It has been argued however, that the earliest existent Egyptian texts for funerals and coronations, some dating as far back as 3000 BC are really plays. See also: [EARLY THEATRE, GREEK], [EARLY THEATRE, ROMAN].

EARLY GLASS - (c 2500 BC)

The most reliable research places the invention of glass in the third millennium before the birth of Christ, in Mesopotamia, (or present-day Iraq and Syria). The earliest known glass makers worked in Mesopotamia, as far back as 2500 BC, crafting beads and other small objects. Hollow vessels do not appear before about 1500 BC.

Mix sand, soda and lime, cook and cool, the results: glass. Natural glass can sometimes be created with little more than a strike of lightning on a sand beach. It appears in the form of thin tubes called fulgurites. There are also tektites: small, rounded bodies of glass formed as a result of meteorites crashing to earth. Among natural glass, the most prevalent is obsidian. Shiny and dark, it is born in the fires of volcanoes and was first used by humans to make tools, more than a million years ago. The Romans introduced glass blowing, about 50 BC. See also: [MEDIEVAL STAINED GLASS].

RE (THE SUN GOD) - (c 2300 BC)

(Also: RA) - The Egyptians believed that at night the sun god, Re, would travel through dark regions beneath the world where his ship faced destruction by a dragon named Apophis. A papyrus in the British Museum records a ceremony based on this theme, dating from about 2300 BC. Although Egyptian art survives in some quantity, direct illustrations of early rituals do not. Dancing and music, however, the secular entertainment of the pharaoh's courts are well illustrated by paintings and other artifacts.

STONEHENGE - (c 2000 - c 1500 BC)

Early man considered himself to be a child of the sun. Worship of the sun became part of early civilization.

Stonehenge was built on the Salisbury Plain (England) between about 2000-1500 BC. From the stones and other existing landmarks, archeologists have long puzzled over its meaning. Dr. Gerald S. Hawkins, (astronomer) showed in 1963 (with the aid of computers) that the stones were aligned to indicate the solstices and the beginning of seasons, and to predict eclipses of the sun and moon.

SUNDIAL - (c 1500 BC)

The sundial is an instrument for measuring time, by means of location of a sun shadow, cast by a marker. A sundial consists of two parts; a gnomon and a dial plane. The gnomon is the shadow producing device. The principal of the sundial was discovered about 1500 BC and allowed early man to divide the day into hours. The first hemispherical sundial was described about the 3rd Century BC by Chaldean astronomer Berossus. Sundials were used for determining the time until the 18th. Century, when clocks and watches became available.

TEMPLES - (1000 BC)

Although early Roman temples date as far back as 2000 BC, Greek temples were built after the Dorian immigration (before 1000 BC). One of the best examples is the Parthenon, from the 5th Century BC.

Most Greek temples were usually oriented to the east to illuminate the statues within through the doorways at sunrise.

OIL POTTERY LAMPS - GREEK - (600 BC)

After the natural oil lamp, then the crude worked lamp, pottery lamps followed. Early Greek pottery and were hand-modeled. Handles first appeared on Minoan lamps, and on the first Athenian lamps of the 7th Century BC. In addition to hand-modeling, later lamps were also manufactured by pottery wheel and molding techniques. Both of these techniques became far more popular than the hand-modeling method.

Pottery lamps were a cheap and practical means of illumination, easy to produce, easy to use, but rather messy to handle. The oil would often ooze from the wick hole and run down the outside of the lamp.

During the 6th, 5th and 4th centuries BC, Athens was a major manufacturer and exporter of high quality poetry lamps. Lamps similar in basic design may still be used today, in some parts of the world.

Additional Reading: Greek and Roman Pottery Lamps, by Donald M. Bailey, The British Museum, 1972.

PYTHAGORAS - (c 582 - c 500 BC)

Pythagoras was a Greek philosopher and mathematician who was born in Samos. He founded the Pythagorean School that emphasized the study of musical harmony and geometry. He also put forth the 'Particle' theory of light. This assumed that every visible object emits a steady stream of particles, that bombard the eye. Pythagoras suggested that "light consists of rays that acting like feelers, travel in straight lines from the eye to the object, and the sensation of sight is obtained when these rays touch the object", much like the sense of touch.

HERACLITUS - (c 535 - 475 BC)

Heraclitus - Greek philosopher - "The world, an entity out of everything, was created neither by gods nor by men, but was, is and will be eternally living fire, regularly becoming ignited and regularly becoming extinguished" (The Cosmic Fragments #20, c 480 BC).

OIL RESERVOIR LAMP - (500 BC)

Gradually the body of the oil lamp closed, forming a completely enclosed reservoir, by about 500 BC. The oil reservoir lamp consisted of pottery or metal bowls with one or more wicks projecting through openings in the spouts and a cover to keep the reservoir from being spilling or being ignited. The cover also helped keep rats and mice from drinking the oil and prevented insects that were attracted to the light, from falling into the oil.

Artisans of that day found in the oil lamp, an intriguing medium for their artistic expression. Early Greek, Roman and Egyptian lamps are highly artistic in design.

Additional Reading: Greek and Roman Pottery Lamps, by Donald M. Bailey, The British Museum, 1972.

EARLY THEATRE, GREEK - (500 BC)

The first great theatrical age in the history of Western civilization is that of Greece in the 5th Century BC. It was there that tragedies and comedies were first performed by actors, not by priests, in special buildings. The Greeks built open air theatres, and used natural daylight and sunlight for their lighting. In the Greek theatre, lanterns were used to show that the scene was set at night. Early theatres were constructed from wood. Later, theatres (300 B.C.) were constructed from stone.

Additional reading: Theatre Design & Technology, December 1991. Additional reading: A Concise History of the Theatre, P.Hartnoll 1974.

EURIPIDES - (484 - 406 BC)

Euripides (Greek) a contemporary of Sophocles was the last great writer of Greek tragedy. Eighteen plays survive (out of a possible ninety-two.)

PLATO - (c 427 - c 347 BC)

Plato was a Greek philosopher and one of the most creative and influential thinkers in Western philosophy. Born to an aristocratic family in Athens, he eventually became a disciple of Socrates. The Platonic School complicated the theory of light, by supposing that vision was produced by rays of light that originate in the eye and then strike the object being viewed.

ROMAN - LIFE & LIGHT - (400 BC - 80 AD)

From the earliest days, light became a part of religious ceremony. In the pagan temples of the Romans, The Vestal Virgins tended the everlasting light. Apparently, any of the virgins who broke their vow of virginity, would be buried alive.

In 264 BC, the first year of the war, gladiatorial combats were made part of the 'games', prisoners being allowed to hack each other to death for the amusement of the people, instead of being executed. By the first Century AD there were sixty days of games at various times of the year. Three centuries later, the figure had risen to one hundred and seventy-five days a year. By then, the games had moved from temporary to permanent buildings and started to offer more extravagant horrors. Crocodiles, bison, zebra, lions and tigers were imported to fight each other or the gladiators. In 80 AD, Titus dedicated the 'Colosseum" in Rome with games lasting a hundred days, in which some nine thousand animals were killed in 'hunting scenes'

ARISTOTLE - (384 - 322 BC)

Aristotle was a Greek philosopher and scientist. He was also a pupil of [PLATO]. He had a different theory of light from the Pythagorean School. Aristotle concluded that light travels in something like waves.

Regarding the relationship between color and sound (music), he wrote: "colors may mutually relate like musical concords for their pleasantest arrangement like those concords mutually proportionate".

'The whole terrestrial region, (wrote Aristotle in his Meteorologica) was composed of four 'bodies': fire, air, water and earth'.

According to Aristotle, a play is 'an imitation of an action, not the action itself".

Additional reading: "Aristotle's Works" were translated into English and edited by Sir David Ross and S.J. Smith, 12 vols (New York & London, 1910-1952).

COLOR AND MUSIC (SOUND) - (c 350 BC)

Many people over the years have tried to find a relationship between the color of light and music (or sounds).

See: [ARISTOTLE, NEWTON, CASTEL, HOFFMAN, WILFRED, and COLOR ORGAN].

EUCLID - (320 - 275 BC)

Euclid, (probably Greek) a mathematician studied light and followed the teachings of [PLATO]. He was to greatly influence the development of the field of optics. He described the behavior of light and in his book on optics, (in his twelve postulates), he anticipates the important ray theory. The first postulated stated: The rays emitted by the eye, travel in a straight line.

Euclid also gathered all the geometry of his time into a single logical system, in his book 'Elements'. It is still the basis of geometry taught today.

The speed of light must be very high, Euclid believed, because you can close your eyes (thus making the things you are looking at disappear!) and then, when you open them again, even the distant stars appear instantly.

EARLY OPTICS & LENSES - (c 300 BC)

The earliest known lenses to the Greeks and Romans consisted of glass spheres filled with water. These early lenses were used as 'burning lenses'. True glass lenses were unknown at this time. It wasn't until the end of the 13th Century that glass lenses were manufactured in Europe.

Today, most lenses are made from special types of high quality glass known as optical glass. This glass is generally free of internal bubbles, and imperfections. First a glass 'blank' is cut from a block of optical glass. Next the blank is ground into rough shape by grinding on a cast iron plate, covered with a mixture of abrasive material and water. Convex or concave surfaces are formed using special curved grinding tools. The final process of manufacture is polishing, a process accomplished on a pitch covered iron tool coated with jeweler's rouge and water.

ARCHIMEDES - (287 - ??? BC)

Archimedes a Greek, discovered the principal of buoyancy in his bathtub. He invented a device for lifting water (Archimedes Screw) and he built many devices for the study of astronomy.

In 212 BC as the Roman republic invaded Syracuse in Sicily, Archimedes is said to have built large focusing mirrors that reflected and directed intense sunlight onto the Roman ships in the harbor, setting them alight. (This is doubted by most historians).

PHAROS OF ALEXANDRIA (LIGHTHOUSE) - (c 280 BC)

The Pharos of Alexandria was a lighthouse more than 134 m. (440 ft.) tall, that stood on an island at the entrance to the harbor at Alexandria, Egypt. A fire burned at the top as a signal to ships on the Mediterranean. The Pharos has been called "archetype of every modern lighthouse." It lasted to about the 14th Century AD.

HERO OF ALEXANDRIA - (c 150 BC)

Hero of Alexandria, was a Greek scientist and mathematician, probably born in Egypt. He wrote at least 13 works on subjects concerning applied mathematics, mechanics and physics. Although [EUCLID] could explain plane surface reflection, Hero of Alexandria is often credited with discovering the properties of reflection of light, and putting forward the law. {1ST REFLECTION}

The early Greeks, assumed that light traveled in straight lines. Although the Pythagorean school assumed that every visible object emits a steady stream of particles, [ARISTOTLE] on the other hand, concluded that light travels in waves.

EARLY THEATRE, ROMAN - (55 BC - 200 AD)

The Romans, developed their theatres after the Greeks, however there were a number of differences. Rome theatres were built on flat ground, not on a hillside, and had a vast wall of surrounding masonry, often elaborately decorated. The first stone theatre in Rome was built by Pompey in 55 BC. Soon after, other theatres were built, each steadily becoming more vast and ponderous. The 'Theatre at Sabratha' (North Africa), was built about 200 AD and had a typical Roman semicircular orchestra (seating), raised stage and elaborate three story stage facade (frons scaenae).The Roman theatre had no real great dramatists. Plays were read and quoted from, but not acted.

The Romans continued to use natural light as the main source of lighting for their plays. The Romans also used torches and fire in their presentations to indicate the time of day.

ROMAN - LIGHT AND ARCHITECTURE - (c 15 BC)

The use of natural light in buildings was the domain of the architect. The Roman Architect Vitruvius devoted a whole chapter to natural lighting in his text book 'De Architectura' written about 15 BC.

WORLD POPULATION - (0 BC) - 250 million people.

0 BC - BIRTH OF CHRIST

LIGHT AND THE BIBLE

There are more than 200 references to the word 'light' in the Bible. About 75 of these occur in the new testament. The book of Job contains the most references (over 25) and the book of Psalms has about 25 references to light. In the new testament, the Gospel of John has the most references (about 16),

Light was the first of God's creations, according to the book of Genesis. "And God said, let there be light, and there was light". (Old Testament, Genesis, i,3.)

God saw that the light was good, and he separated the light from the darkness. (Old Testament, Genesis, i,4.)

"Speak to Aaron and say to him 'When you set up the seven lamps, they are to light the area in front of the lampstand'". (Old Testament, Numbers 8.2.

The Bible, Numbers 4.9: "They are to take a blue cloth and cover the lampstand that is for light together with its lamps, its wick trimmers and trays, and all its jars for the oil used to supply it."

"to the land of deepest night, of deep shadow and disorder, where even the light is like darkness". Job 10.22.

"What is the way to the abode of light? And where does darkness reside?" Job 38.19.

"His snorting throws out flashes of light, his eyes are light the rays of dawn". Job 41.18

Light was identified throughout the New Testament with the nature of God, himself. "The word is light that the darkness cannot extinguish, and this light illuminates every man.....We are the children of light, who have put aside the world of darkness."

"The first creature of God in the works of the days, was the light of the senses, the last was the light of reason". - (Francis Bacon, Essays of Truth.

HORN LANTERN - (c 100 AD)

The horn lantern provided a portable light source. It was not only suitable for moving about outdoors, it was also no doubt used for moving around safely indoors. The lamps were made from the working of horns from cattle into transparent plates and are described in detail by Plinty the Elder (1st Century A.D.) and the lamps were clearly referred to even earlier by Plautus (254?-184 BC).

PTOLEMY, CLAUDIUS - (c 100 - c 170 AD)

Claudius Ptolemaeus, also, Ptolemy (tol-e-mi) of Alexandria was a Greek who lived in Egypt in the 2nd Century of the Christian era - and may have merely recorded the ideas of others. Ptolemy developed a theory of the planets about AD 150. Ptolemy was also able to measure the bending of a beam of light as it passed from air into water or glass. It is known that whatever observations Ptolemy may have made, he was not led to the correct reflection laws, as later discovered by [SNELL] in 1621. {1ST REFRACTION}

THEATRE IN THE MIDDLE AGES - (400)

There is little known of the Romanesque and Byzantine theatre. In the 5th Century A.D. all performers of mime were excommunicated; in the 6th Century Justinian closed the theatres and the end of theatrical entertainment was finally sealed with the arrival of the Barbarians in 568 A.D. For almost 1000 years, very little theatre or performance took place.

CANDLE - (c 400)

The invention of the candle dates back to about 400 A.D., perhaps somewhat earlier. Relatively few candles were used in the home until about the 14th Century, however they were an important symbol of the Christian religion. The best candles were made of beeswax and were used chiefly in church rituals because the bee was regarded as a symbol of purity. But because beeswax was expensive, crude tallow candles had to be used by the common people. Tallow was smelly and smoky. The candles dripped badly and generally gave a feeble light.

MEDIEVAL STAINED GLASS - (905)

According to legend, glass is a Phoenician discovery and, therefore, more than 2000 years old. As recorded in literary sources, it was often used for windows in late antiquity and early Christian times. The German monk Theophilus Presbyter in his "Schedula diversarum artium", of the tenth or eleventh Century, says that the stained-glass window, was a craft long practiced in France, and the chronicle of the St. Remi in Reims, dating from 905, says the window in the church depicted various scenes.

The art of stained glass reached its height in the Middle Ages, between 1150 and 1250. Outstanding examples of 12th Century stained glass can be found in the windows of such churches as Saint-Denis, in Paris, and Canterbury, in England. Excellent examples of 13th Century works include the windows at Chartres and the Saint-Chapelle in Paris.

ALHAZEN (IBN AL HAITAM) - (965 - 1039)

Abu Ali Mohamed ibn al-Hasan Ign al-Haytham (also: ibn al-Haitam) was an Arabian scientist and scholar, also known as 'Alhazan'. He was one of the earliest, to write and describe optical theory. He studied light, the nature of vision, the eye, and solar and lunar eclipses. His early experiments led to a forerunner of the [CAMERA OBSCURA] which he used to prove that light travels in straight lines. He also studied reflection and refraction, and published a book on optics in 1038. Alhazan's work became an historical reference work in the evolution of optics.

His treatise on optics was translated into Latin by Witelo (1270) and afterwards published by F. Rismer in 1572 with the title "Opticae Thesauris Alhazeni Libri VII cum ejusdem libro de crepusculis et nubium ascensionibus" Other manuscripts are preserved in the Bodleian Library at Oxford and in the Library of Leiden.

CAMERA OBSCURA - (c 1000)

The development of the modern day camera is based on the early discovery of the camera obscura. Although it is difficult to prove the original inventor, certainly one of the first to describe and use the principles of the camera obscura, was [ALHAZEN], in 1038. Others including Roger [BACON], and Giovanni [PORTA], also are credited with the invention or development of the camera obscura. The principals of the camera obscura were frequently used by early painters and artists, in their studies of architecture, much like a photograph is used today.

The camera obscura at first was simply a small room, completely darkened and light-tight. A small pinhole was made in an outside wall and the brightly illuminated exterior scene would be projected on the opposite wall. No lens was required. The image was inverted, or projected up-side-down. The principal of the camera obscura evolved into a small box, with drawing paper being used to trace the image and by about the year 500, artists began using the device as a drawing aid. Some versions were made with an internal mirror to reverse the image and turn it right side up again. Over the years, the camera obscura became smaller in size and eventually evolved into the modern day camera.

MEDIEVAL RELIGIOUS DRAMA - (11th Century)

After the disappearance of classical drama, it is within the Church itself, that theatre is revived in the Middle Ages in the form of the liturgical or church drama of western Europe. The first liturgical plays were written for performances by priests and choir boys in a church. The alter with its crucifix was always central to the playing area. On stage right was Heaven, on stage left was Hell. Several other scenes, were arranged in between.

MEDIEVAL THEATRE - (12th & 13th Century)

It was during the late 12th and 13th centuries that plays began to move out of the Church. Productions continued to become more elaborate and complicated. They continued to demand a great number of properties and working machinery. The raised wooden platform would conceal traps, there were cranes by which God and his angles could descend from Heaven, and in the Mons play of 1501 the mechanism of Hell-Mouth which opened to belch out clouds of smoke and closed to swallow up the damned, was so complicated that it took seventeen men to work it. The stage carpenters thought nothing of producing floods, fires and earthquakes. Realistic executions were called for, with bloody wounds, severed heads and limbs. Costumes were elaborate and sometimes splendidly embroidered.

1200

MAGNIFYING GLASS - (1200's)

- See: [BACON, ROGER]

SPECTACLES (EYEGLASSES) - (1200's)

Credit to developing spectacles generally goes to Roger [BACON]. One of the earliest paintings to show spectacles is by the artist Jan van Eyck and dates to 1436.

BACON, ROGER - (c 1214 - c 1294)

Bacon (place of birth unknown) was an English monk, scientist and scholar and was also known as Doctor Mirabilis. Details of his life are obscure however he did make a great impression on the learned minds of his time.

Bacon is usually given credit for developing the magnifying glass. He is also variously credited with the discovery of eyeglasses. Others also give him credit for developing the [TELESCOPE], the [CAMERA OBSCURA] and gunpowder. He followed the work of [ALHAZAN] and spoke of concave and convex lenses. He also expressed interest in the natural sciences, mathematics, perspective and astronomy.

He wrote in his 'Opus Majus': "...pictures could be projected into space, into air where it could become visible for the multitudes."

1300

1400

LEONARDO DA VINCI - (1452 - 1519)

A scientist and artist, Leonardo did much to study the natural forces and actions of nature. Leonardo's world reached from philosophy to mathematics to physics, optics, botany, zoology, mechanics, hydraulics, astronomy, and other scientific areas. He investigated the nature of light and studied reflection, refraction and mirrors. He studied the structure and anatomy of the human eye and compared it to the [CAMERA OBSCURA]. Leonardo also attempted to fly, but failed. He was an excellent painter. In fact, he was a true genius.

Born in 1452, Vinci, Leonardo lived at first just outside of the Italian village of Vinci. In 1469, Leonardo's father took him to Florence to continue his schooling. He outshone his fellow pupils at every skill and in 1472, when he was 20, was accepted into the guild of painters, allowing him to seek independent commissions for his work.

Leonardo was a master of light. As a painter, he studied; light, reflection, shadow and color in detail. The presents and importance of light is clearly evident in Leonardo's work. Leonardo produced a great many sketches and paintings. He left behind, however, very few completed works, most of which can be found today in the Louvre museum. da Vinci is probably best know for his painting of the 'Mona Lisa', painted between 1503-1505. He kept this painting at his side, until the day he died, as he claimed it was unfinished. This painting is now perhaps the most famous painting in the world.

There is evidence from his note books that Leonardo may have combined a negative and positive lens to observe the Moon. Unfortunately he kept his notes secret during his lifetime and they were edited much too late to have any influence on [GALILEO] who did extensive work with the telescope in the early 1600's.

Leonardo was also left handed and wrote his notes in mirror writing (reversed).

Additional Reading: National Geographic, Vol. #152, Sept. 1977, Leonardo da Vinci: A Man for All Ages, James L. Amos.

COPERNICUS, NICOLAUS - (1473 - 1543)

Copernicus, (Poland) in 1512, correctly placed the sun at the center of the solar system. Finally, the world was free from the misconception that all other heavenly bodies revolved around a stationary earth. He still believed however that the planets orbited in perfect circles. It wasn't until 1609 that Johannes [KEPLER] correctly identified the orbits as being elliptical in nature, instead.

SERLIO, SEBASTIANO - (1475 - 1554)

Serlio (Italian), a painter then architect was the first published theorist of the Renaissance theatre. His six chapters on how to build stages and scenery appeared first in Paris in 1545 under the title 'Le second livre de la perspective'. He also developed a system of 'color filters', using candles placed behind translucent containers of color liquid. He went on to give recipes and recommendations for the use of specific colors. By using a brightly polished barber's basin behind a torch or candle, he developed an elementary spotlight, with a round bottle serving as the lens. {1st EARLY SPOTLIGHT}

MAUROLYCUS, FRANCISCUS - (1494 - 1575)

Maurolycus wrote on the subject of light in 1554 in his "Light on the Subject of Light".

AGRICOLA, GEORGIUS - (1494 - 1555)

Agricola was a German scientist and the founder of petrology and the science of mining (mineralogy). He studied medicine in Italy and became town physician in the mining town of Joachimsthal. He wrote on the subject of the color of flames when common salts were dropped into them. He concluded that "it must be possible to obtain from the color of a flame enlightenment concerning the materials burning therein." We know today that is the sodium in the salt that causes yellow flames, potassium salts, when burned produce a violet color, strontium salts red, and barium salts, green. See also [MELVILL].

1500

VESALIUS, ANDREAS - (1514 - 1564)

Andreas Vesalius (vi-sa-le-as) was a Flemish physician born in Brussels, Flanders. His dissections of the human body and descriptions of his findings helped to correct misconceptions held since ancient times and are the basis of the foundation of the modern science of anatomy. In 1543 he published his 'Fabric of the Human Body" and clarified many obscure details, including those of the human eye. Much of his work is noted for its remarkable drawings of the body.

DI SOMI, LEONE - (1527 - 1592)

Leone di Somi was a stage artist and a noted physician. In 1565 in Mantua, he wrote his 'Dialogues on Stage Affairs' giving valuable insights into period theatre design practices of the time. Di Somi is also credited with being the first person to discuss the advantages of the darkened auditorium during a stage performance.

PORTA, GIOVANNI - (1533 - 1615)

Giovanni Basttista Porta - Although the invention of the [CAMERA OBSCURA] has been attributed to a number of people, [ALHAZAN, BACON, LEONARD0], before him), Porta often also is given credit. In 1558, Porta published a book "Magis Naturalis" and describes the use of convex lenses in order to improve the formation of images. In 1593 Porta wrote another book "De Refractione", which tried to explain the theory of lenses.

GRECO, EL - (1540 - 1614)

El Greco (a pupil of Titian), became one of the most remarkable exponents of individualism, that can be found in the history of art. El Greco went his own way, free from any fashion or trends in painting. He introduced into his work expressionistic ideas, in regards to both form and color.

It is often thought that his elongated figures were attributed to astigmatism. Others dispute this and claim that X-ray evidence shows that the elongated paintings were applied to non distorted drawings.

BRAHE, TYCHO - (1546 - 1601)

Tycho Brahe (Danish astronomer) was an early observer of the heavens. Night after night, for more than twenty years he studied and recorded the position of the planets and the stars. Near the end of his life, he hired an assistant, Johannes KEPLER, an excellent mathematician. Using Brahe's data, Kepler formulated three laws of planetary motion. The data accumulated by Brahe was superior to all other available astronomical measurements, made until the invention of the telescope in the early 17th Century (about 1600).

INGEGNIERI, ANGELO - (c 1550 - c 1613)

In 1598, Angelo Ingegnieri, a stage designer, published his views in a work entitled "Dramatic Poetry and How to Produce Plays". He calls lighting 'one matter of supreme theatrical importance'. The lighting of the actors' faces was especially important. Ingegnieri was also an advocate of the darkened auditorium, during a performance.

GALILEO, GALILEI - (1564 - 1642)

Galileo was an Italian astronomer, mathematician and physicist from Pisa who developed the scientific method of studying natural events. He studied light and observed the heavens with a telescope and in 1609, discovered that Jupiter had satellites and that Venus displayed phases like the moon. Although Galileo did not invent the telescope he did invent modern astronomy.

He also studied motion and acceleration and defined the laws of motion He was an outspoken advocate of Copernicus's theory that the sun forms the center of the universe, which led to his persecution and imprisonment by the Inquisition in 1633.

SHAKESPEARE, WILLIAM - (1564 - 1616)

The English dramatist and poet, William Shakespeare was the author of the most widely admired and influential body of literature by any individual in the history of western civilization. His work comprises 36 plays, 154 sonnets, and 2 narrative poems.

Very little is know about the life of William Shakespeare. Born perhaps in Stratford-upon-Avon, he married at eighteen and soon went to London where he became first an actor then a playwright and a shareholder in the Globe Theatre, where many of his plays were performed. It was indeed fortunate that his plays were printed, as none of his manuscripts survived.

During a play in Shakespeare's day, attendants were assigned the task of caring for the candles. Candle wicks needed to be trimmed constantly, to keep the flame from smoking. To keep these candles burning brightly, these attendants were constantly crossing the stage, even at the most tense moments of the drama, to trim the wicks.

Shakespeare wrote: "Mary, sir, she's the kitchen wench, and all grease; and I know not what use to put her to, but to make a lamp of her and run her by her own light. I warrant her rags, and the tallow in them will burn a Poland winter". (Comedy of Errors iii.ii).

"Light, seeking light doth light of light beguile".
(Love's Labours Lost, i,i.)

RENAISSANCE THEATRE - (1565 - 1675)

During the Renaissance, theatre in Europe flourished. Natural light, the torch, the oil lamp and the candle, were still the principal sources of illumination. Gradually, theatre began to move indoors, from the palace gardens, into the great halls of the ruling nobles. Chandeliers with candles above the stage and the auditorium were used for general lighting. Lighting along the front edge of the stage was (later) provided with candles or oil 'float' lamps. Candles behind the proscenium, were used to light the scenery.

The first permanent classic theatre was the Teatro Olimpico, which still survives today in Vicenza, Italy. Built between 1580-1584, by the famous Italian architect, Andrea Palladio, the auditorium was originally open to the sky. The first theatre with a proscenium arch and a front curtain, (as we know it today) was the Teatro Farnese, build at Parma about 1618. During this period other major design elements of the 18th and 19th Century theatre were developed, including auditorium design, stage sets, wings with flats, the orchestra pit and auditorium balconies. Renaissance Italy was the birthplace of lighting specifically devised for stage productions.

KEPLER, JOHANNES - (1571 - 1630)

Kepler was a German astronomer and mathematician. A contemporary of [GALILEO] he is often credited as being the true founder of modern astronomy, and the first to explain the laws of natural planetary motion. In 1604 Kepler compared the eye to a camera, (a darkened chamber). In 1609 Kepler showed that the earth's orbit was elliptical.

SABBATTINI, NICOLA - (c 1574 - 1654)

Nicola Sabbattini was an architect, theatre designer and painter at the court of Urbino, Italy. He published his famous 'Practica' or 'how-to' on theatrical devices in two volumes (1637 and 1638). His Practica is the first handbook on the art of scenography for the practicing theatre technician. He describes a number of techniques relating to lighting, illumination, scenery and special effects. He describes in detail the need and placement of footlights and the arrangement of other lighting around the stage and auditorium. He even shows (drawing of 1638) a mechanical method of lowering cylindrical metal hoods around burning candles, to cause them to dim. The publication of this text represented a significant step in the evolution, awareness and use of light in the theatre as an art form.

JONES, INIGO - (1576 - 1656)

Jones was England's first major architect. He was born in London on July 15, 1573. Between 1600 and 1603 he visited Italy where he was influenced by the architecture of the Romans and especially as adapted by the Italian architect Andrea Palladio.

Returning to England, he began in 1605 a long association with the English court as a theatre designer and architect. He also introduced the classical manner of Palladian architecture, which he had studied.

Between 1605-1613 he produced a number of elaborate stage and costume designs for the theatre. As a theatre designer, he brought the spirit and vitality of the Italian theatre to lavish masques at the British court. He also became a master at lighting and created many spectacular effects for his productions.

He was also an architect of theatres, one of which still exists today, the Banqueting House. This is considered to be Britain's oldest theatre, built in 1622 with a massive cellar underneath, to support the large stage and the one hundred stage hands required to work it.

Additional reading: Ian Mackintosh, Tabs, September 1973.
Additional reading: Microsoft Bookshelf 97 Encyclopedia.

ELIZABETHAN THEATRE - (1576 - 1640)

The first permanent theatre in London was built appropriately enough, by a carpenter, James Burbage, who was also a part time actor, obviously a man born for the theatre. One of his two sons, the younger, Richard, was the first leading English actor, the creator of Hamlet, Lear, Othello and Richard III, while the elder, Curthbert, acted as his brother's manager. The building which the elder Burbage erected in 1576 was known simply as 'The Theatre'. It was an enclosed structure of wood, which because of opposition from the Lord Mayor of London, was built outside the city boundary.

The most famous Elizabethan theatre, is the 'Globe' built by Burbage's sons on London's South Bank in 1599, with timber from 'The Theatre'. It was here that most of Shakespeare's plays were produced and it was after a performance of Henry VIII in 1612, that the theatre was destroyed by fire. It was rebuilt the following year, and remained in use until it was demolished in 1644. In 1640, the Puritans effectively put an end to theatre until the end of the war in 1648.

As in Greece, there were no women on the Elizabethan stage. Boys, specially selected for their slight, graceful build and light voices, were apprenticed to older actor's and trained to play such parts as Juliet, Rosalind, Viola and Portia. As in Italy, all the actors had to be dancers and singers.

MICROSCOPE - (1590)

The microscope was invented about 1590 by Zacharias Jenssen of Holland. This was the first compound microscope, using two lenses. The microscope wasn't really put to serious use until in 1665, when the English scientist, Robert [HOOK], published his 'Micrographia', the first documentation of the microscopic world.

FURTTENBAC, JOSEPH - (1591 - 1667)

Also: (JOSEF FURTENBACH) a German architect, in 1628 described a stage sloping toward the audience. In front was an orchestra pit with a wall masking the musicians from the audience. He also developed a mechanical method of blacking out candles by remote control and a type of reflector for the candle, using mica. He gives very detailed descriptions of lighting instruments.

SNELL, WILLEBROD, VON ROIJEN - (1591 - 1626)

Willebrod Snell (commonly known as Snellius) was a Dutch mathematician and physicist. He is known for his discovery of the simple relationship between the angle of incidence and the angle of refraction for a ray of light crossing from one medium to another. Although he never published his discovery, (Snell's Law), he merely lectured on it. His discovery (1621) of the law of refraction was of significance for the study of the nature of light. Now crude optical instruments, already in use (i.e. [TELESCOPE]), could now be further explained.

DE LA TOUR, GEORGES - (1593 - 1652)

Georges de la Tour (French) was a painter of Louis XIV's time. Many of his (later) works show a masterful, almost obsessive use of artificial light. He was born in Vic-Sur Sille in 1593 and died in Lun‚ville in 1652.

DESCARTES, RENE - (1596-1650)

Rene Descartes (da-kart) was a French philosopher, scientist and mathematician. In 1637 he published his "Les Meteores" in which there is an admirable explanation of the [RAINBOW], showing how both primary and secondary colors are formed. Descartes study of optics led him to the independent discovery of the fundamental law of reflection, that the angle of incidence is equal to the angle of reflection. His essay on optics was the first published statement of this law.

VELAZQUEZ, DIEGO RODRIGUEZ DE SILVA Y - (1599 - 1160)

Velazquez was a Spanish painter with an extraordinary technique and mastery of light. He painted still lifes, portraits, and historical scenes, such as 'The Surrender of Breda' (1635).

1600

AVERAGE LIFE EXPECTANCY - 33 YEARS in 1600

TELESCOPE - (c 1600)

Hans Lippershey was a Dutch lens grinder and maker of spectacles. He is usually credited with the invention of the first telescope about 1600 and he applied for a patent in 1608. About a year later, various lens grinders of northern Europe, were making telescopes. Records show that the telescope was further developed by [GALILEO] and by others. [BACON] (in the 1200's) is also sometimes given credit for discovering the first telescope.

KIRCHER, ATHANASIUS - (1601 - 1680)

Kircher was a professor of mathematics in Rome, about 1650. Kircher is often given credit for the invention of the [LATERNA MAGICA], the earliest form of projection device (about 1645). [HUYGENS] and [WALGENSTEIN] are also given credit). Kircher published a number of books, and also described the [CAMERA OBSCURA], lenses and optics. Kircher was also one of the first to experiment with moving images. He was also one of the first to try and correlate and relate light to sound.

REMBRANDT VAN RIJN - (1606 - 1699)

The art of oil painting originated in Holland. Rembrandt Harmenszoon van Rijn was born in Leyden, in the province of Holland, on July 15, 1606. Rembrandt was to become the supreme dramatist of light. He saw man isolated in nature and he revealed man in nuances of light and dark. Rembrandt remains unrivaled in his understanding of the complex world of feelings and emotions. Although the source of light is seldom seen in his paintings, his figures often 'radiate' light as if they were the source of light itself.

Many of his works show very dramatic lighting. A perfect example is 'The Woman Taken in Adultery' which shows great contrast and dramatic side lighting.

GRIMALDI, FRANCESCO - (1618 - 1663)

Grimaldi, in Italy, discovered optical diffraction and observed its periodic nature. {1ST DEFRACTION}

BOYLE, ROBERT - (1627 - 1691)

Robert Boyle, physicist and chemist, is often referred to as the father of modern chemistry. He invented the vacuum pump and used it in the discovery of what is known as Boyle's law. Boyle was also a pioneer in the laboratory study of the field of [BIOLUMINESCENCE]. In 1667, he showed that the light of luminous bacteria and fungi goes out if the organisms are deprived of oxygen.

HUYGENS, CHRISTIAN - (1629 - 1695)

Huygens (hoi'gens) was a Dutch scientist, who thought that light consisted of waves, not particles, as did [NEWTON]. Both theories had strong arguments in their favor.

His wave theory suggested that light results from the molecular vibration in the luminous material. Further, that vibrations were transmitted through an 'ether' as wavelike movements (like ripples in water). Huygens concluded that the result of these transmissions acted on the retina, stimulating the optic nerves to production vision.

His numerous, original discoveries won him wide recognition and honors among the scientists of the 17th Century. He discovered a new method of grinding lenses, and using the sharper definitions obtained, he discovered a satellite of Saturn and was able to provide the first accurate description of the rings of Saturn.

In 1678 Huygens discovered the polarization of light by double refraction in calcite. Huygens is often also given credit for the development of the projector [LATERNA MAGICA].

HOOKE, ROBERT - (1635 - 1703)

Hooke was an English physicist who discovered the law of elasticity, known as Hook's Law. He also did research in a remarkable variety of fields. Hooke was educated at the University of Oxford and later went on to assist the English physicist Robert Boyle in the construction of the air pump. In 1662 he was appointed the curator of experiments of the Royal Society and served in this position until his death. After the great fire of London in 1666 he was appointed surveyor of London and was responsible for designing many new buildings. Hooke was also a pioneer in microscopic research and published his observations, which included the discovery of plant cells.

RAINBOW - (1637) See: [DESCARTES, RENE] and [NEWTON].

PURITANS - (1640)

In 1640, the Puritans effectively put an end to theatre in Britain, until the end of the war in 1648.

NEWTON, SIR ISAAC - (1642 - 1727)

Sir Isaac Newton was an English scientist and mathematician who greatly contributed to many fields of science including; motion, gravity and optics. He was first to formulate the corpuscular theory of light. Newton said that luminous bodies radiate energy in particles or corpuscles, and that these particles are ejected in straight lines. The particles then act on the retina of the eye in a manner to stimulate the optic nerve and produce the sensation of vision in the brain. Newton was born the same year that [GALILEO] died.

In 1666 Newton at the age of 23, performed his famous prism experiment. He noticed and recorded that sunlight is white light that contains all the colors of the spectrum. In 1704 he published the first edition of his famous book 'Opticks'. Newton correctly identified the principals of refraction associated with his experiment in that light is bent as it travels from one medium to another at a slight angle, dependent on its wavelength. He didn't know that he was repeating what [LEONARDO DA VINCI] had noted down, in mirror writing, approximately 200 years earlier.

Newton, like others before him also tried to discover a link between light and color and between light and sound. Newton divided the visual spectrum into seven colors. He considered that these divisions corresponded to the diatonic scale. He wrote: " Considering the lastingness of emotions in the bottom of the eye by light, are they not of a vibratory nature? Do not the most refrangible rays excite the shortest vibrations - the least refrangible the largest? May not the harmony and discord of colors arise from the proportions of the vibrations propagated through the fibers of the optic nerve into the brain, as the harmony and discord of sounds arise from the proportions of the vibrations of the air?" The answer to Newton's question today, would be no! His color scale was as follows:

Red - C
Orange - D
Green - F
Blue - G
Indigo - A
Violet - B

"Nature and Nature's laws lay hid in Night:
God said, Let Newton be, and all was Light"
(Alexander Pope, 18th Century)

ROEMER, OLAF - (1644 - 1710)

(Also: Olaus and Ole) - The speed of light was roughly calculated in 1675 by the Danish astronomer Olaf Roemer. He used the moons of Jupiter, discovered several years earlier by Galileo to assist in his calculations. His calculations led to an estimate of 132,000 miles per second. Roemer's submitted his work to the French Academy of Science in 1675. He was ridiculed and his work was largely forgotten. Fifteen years after his death the British astronomer James Bradely started out from the same observations that R”emer had made and his thinking ultimately led to a conclusive figure for the speed of light (186,000 miles per second). See also: [SPEED OF LIGHT].

LATERNA MAGICA - (c 1645)

The Laterna Magica (magic lantern) was the first early projection device and a forerunner of the modern slide and motion picture projectors.

[KIRCHER], (in about 1645) is usually given credit for the invention of the Laterna Magica. Although it is very difficult to prove the original inventor, [HUYGENS] and [WALGENSTEIN] are also given credit for invention of the Laterna Magica.

In his book, German historian, Helmuth Wolff wrote: "It is possible to prove the use of the Laterna Magica at the beginning of the 18th Century, that is for the years 1726-27, at the Opera in Hamburg. The designer and architect Thomas Lediard describes these projections very precisely, eliminating any doubts".

WALGENSTEIN, THOMAS - (1650)

Walgenstein (Danish), demonstrated an early projection device [LATERNA MAGICA] throughout Europe and worked with an early projector in Rome in 1650.

RESTORATION THEATRE - (a 1660)

During the interval of Puritan rule in Britain, all of the formerly supported stage productions were suspended (1640). The main source of light in Restoration theatre was usually chandeliers concentrated toward the front of the house, especially over the forestage. The chandeliers were somewhat of a nuisance however, as they had to do for indoor and outdoor scenes alike. Furthermore, they dripped hot grease on both audience and actors.

The candle snuffer was a characteristic figure of these times. Candlewicks needed frequent trimming, regardless of what was taking place on the stage.

GREAT PLAGUE SWEPT ENGLAND - (1664 - 1665).

COLORS OF THE SPECTRUM - (1666)

Color is an electromagnetic wave phenomenon. It is a sensation produced when light stimulates the retina of the eye, and the brain interprets this sensation as 'color'.

Early scientists always considered the primary colors to be relatively large areas of the spectrum: red, orange, yellow, green, blue and violet. However in 1666, [NEWTON], named a 7th color located between blue and violet, as indigo. Aubert in 1865 estimated that the solar spectrum contained approximately 1,000 distinguishable hues. Root in 1881 found 2 million tints and shades can be distinguished.

DISCOVERY OF PHOSPHORUS - (1669)

Phosphorus - from phos-phoros, or 'light bearer'. Hennig Brand (German) discovered the strange new element phosphorus in 1669. A painting by the Englishman Joseph Wright in 1771 shows Hennig on his knees praying, while his dark laboratory is illuminated by the eerie glow of phosphorus, contained in a glass vessel. He obtained the material from human urine.

FIRST - USE OF WING LIGHTS - (1670)

There is reference to candles having been fixed behind the shutters (sliding flat wings), as early as 1670, at the Hall Theatre.

FIRST - USE OF FOOTLIGHTS - (1673)

One of the first recorded use of footlight can be seen in the French painting 'Les delices du genre humain', 1670. The painting of the Comedie Francais in Paris shows a row of small protruding flames along the downstage edge of the stage. Four chandeliers with candles are also shown, hanging above the stage.

Another of the first recorded uses of footlights in the English theatre (also with chandeliers above the stage) can be seen from the drawing (front piece) to Francis Kirkman's 'The Wits', published in 1673. ('The Wits' or 'Sport upon Sport', was a collection of short comedies acted in private halls during the Puritan ban of the theatres between 1642 and 1660.) The footlights are candles (or possibly, oil lamps). Oil lamps usually had two or more wicks in individual containers, and their use certainly predates this print.

POLARIZATION/POLARIZED LIGHT - (1678)

In 1678 [HUYGENS] discovered the polarization of light by double refraction in calcite. Polarized light is a special type of light. It occurs in nature and can also be manmade. Ordinary light consists of a mixture of waves vibrating in all directions perpendicular to its line of propagation (or travel). Polarized light consists of the electric or magnetic waves all confined to one plane. Polarized light can be obtained by reflection (depend on the angle of incidence) and it can also be obtained by double refraction in certain crystals, such as calcite. See also: [POLAROID FILTER] and [ETIENNE, LOUIS MALUS]

CASTEL, PADRE - (1688 - 1757)

Over the centuries, many efforts have been made to compare color to sound and to link the two media into a single systematic language. The French Jesuit, Louis Bertrand Castel claimed that he was inspired by Kircher, and was the first to create an actual [COLOR ORGAN]. Castel called his device 'Clavessin Oculaire'. The device consisted of a remodeled harpsichord with a keyboard. Padre gave his first recital in Paris on December 21, 1734.

Additional Reading: The Art of Light & Color, Tom Jones, 1972.

1700

FRANKLIN, BENJAMIN - (1706 - 1790)

Franklin was an American painter, author, diplomat, philosopher, and scientist. He was born in Boston on January 17, 1706, and at the age of 13 was apprenticed to his brother James, who had recently returned from England with a new printing press. In 1723 he left Boston and moved to Philadelphia, to continue work as a printer. In 1724 he traveled to London (at age 18) and obtained employment from two of the leading printing houses in London. In 1726, Franklin returned to London to resume his trade as a printer.

Always interested in scientific studies, he invented the Franklin stove, and then later in 1747, he began to experiment with electricity. He supported the hypothesis that [LIGHTNING] was an electrical phenomenon, and proposed an effective method of demonstrating this fact. His plan was published in London and carried out in England and France before he himself performed his celebrated experiment with the kite in 1752. He invented the lightning rod and offered an explanation of positive and negative electricity.

In 1784, Franklin also invented bifocals. He was also a critic of the corpuscular theory of light. His research into the nature of electricity helped pave the way for its practical use and resulted in the development of the lightning rod.

GARRICK, DAVID - (1717 - 1779)

David Garrick was the leading figure of the English stage from 1741 to 1776. He was responsible for many innovations in the theatre.

Perhaps the most significant lighting of the eighteen Century was practiced at the Drury Lane Theatre under the management of David Garrick. On his return from the Continent in 1765, Garrick began to institute his so-called reforms at the theatre. While in Paris he was particularly impressed with the lighting and staging techniques at the Paris Opera that he decided to import many of the French stage techniques and lighting equipment, to Britain.

Further Garrick removed the traditional chandeliers, and lighting shifted to sources located behind the proscenium and across the apron. We know in Britain that the sidelight unit had been in use for some years and that the footlight unit had been in use since 1673. Garrick put footlights into the Drury Lane Theatre in 1765 and masked them from the audience with metal screens which also served a reflectors. The notion that Garrick brought the footlight from France is clearly false.

PHOTOGRAPHY, EARLY - (1727)

It had been know for centuries that salts containing silver, when exposed to light would darken. This was discovered by Johann Heinrich Schultz in 1727 and probably by others, earlier. Using Schultz's research, in 1802, Thomas Wedgewood and chemist Humphry Davy studied a method of reproducing drawings on materials that had been treated with silver chloride or silver nitrate. They created the first photogram. The images were 'burned' directly onto a sensitized plate by intense light. The images were not very permanent however. See also: [DAVY].

In 1819, Sir John Herschel discovered that the images could be permanently 'fixed' if they were treated with certain chemicals containing sulfur (hyposulfides). In 1839 Sir John Herschel coined the word 'photography'.

WATT, JAMES - (1736 -1818)

The term horsepower was first used by James Watt, a Scottish inventor and engineer, known for his improvements to the steam engine.

Roughly expressed, a horsepower is defined as 550 foot-pounds of work per second, or 33,000 foot-pounds of work per minute. The metric unit of power is the watt, and even though the term nowadays describes electrical power only it could just as well be used in the automotive field. One horsepower equals 745.7 watts. If an engine lifts a 550 pound object to height of two feet in one second, it delivers two horsepower.

DE LOUTHERBOURGH, PHILIPPE - (1740 - 1812)

De Loutherbourgh, artist and designer received his early training in Paris. In 1771 he was engaged by [GARRICK], the English actor and producer, to design at the Drury Lane Theatre. He often would combine two and three dimensional scenic elements and he also conceived many of his designs in terms of light.

De Loutherbourgh eventually left the theatre to devote his time to an idea known at the time as the 'Eidophusicon'. The Eidophusicon consisted of a miniature theatre constructed to conduct a performance of nothing but scenic effects using light, space, color, movement and sound.

HOFFMANN, JOHANN LEONARD - (1740 - 1814)

Hoffmann, a painter as well as a writer, produced an essay in 1786 where he sought to establish relationships between 'painterly harmony' and 'color harmony'. He also tried to relate color to sound. Hoffman's system was highly theoretical and was based on the concept of polarities or opposites. Hoffman's system was highly subjective and was based on arbitrary personal choices.

GOETHE, JOHANN WOLFGANG VON - (1749 - 1832)

Goethe was a German dramatist, philosopher, poet and pioneer of colorimetry and physiological optics. He was also one of the principal stage directors of the 19th Century. He published a book on color, in 1810. This remarkable book, was exacting in its structure, methods of analysis and the manner of presenting conclusions. In his book "Theory of Color" he recommended the use of complementary colors in to order to help separate costumes from the scenery.

It is in a production of Goethe's Faust, where the use of projection in the theatre - for expressive purposes, is documented for the first time.

"More Light" .... Goethe, on his deathbed.

"Lamps make spots, and candles need snuffing, it is only the light of heaven that shines pure and leaves no stain". - (Goethe, Spruche in Prosa).

Additional reading: Towards a Theatre of Light, E.M. Feher, c 1975. Additional reading: Microsoft Encarta 97 Encyclopedia

MELVILL, THOMAS - (1752)

Melvill (Scottish), was on of the first to make a scientific study of the color of flames, burning various salts. Melvill, like [AGRICOLA] before him, was unable to provide answers to many questions. See also: [SPECTROSCOPE].

MURDOCK, WILLIAM - (1754 - 1839)

William Murdock, a Scotsman is generally regarded as the father of gas lighting. In 1792 he heated coal to produce gas and used it to light his home and office in Cornwall, England.

ARGAND LAMP / AMI ARGAND - (1755 - 1803)

In 1783/4, Ami Argand a Swiss chemist developed the principal of using an oil lamp with a hollow circular wick surrounded by a glass chimney. The wick and chimney improved the combustion of the oil and resulted in a brighter light with less smoke. This was the first real advancement in lamp technology, in thousands of years. The Argand lamp required much more fuel than did conventional oil lamps, limiting their use to the rich, and to public places. The Argand lamp was perfected by Quinquet in 1785.

LIGHTING OF CANDLES - (1761)

In 1761, at the coronation of George III, groups of 3000 candles were connected together with threads of gun cotton, and lit in half a minute. Those clustered below were showered with hot wax and burning thread. See also: [CANDLES].

ADDITIVE COLOR MIXING - (1769)

In 1769, Guyot (French) discovered the additive method of color mixing, by experimenting with transparent colored papers.

YOUNG, THOMAS - (1773 - 1829)

Thomas Young (born in England) was a London physician, linguist, and expert in many fields of science. He read fluently at the age of two (2) At an age of fourteen (14) he was familiar with Latin, Greek, Hebrew, Arabic, Persian, French, and Italian. Young strongly supported the [HUYGENS] wave theory of light, mainly by virtue of his now famous double slit experiment (1801) demonstrating the interference of light waves. He was also the first to describe and measure astigmatism (1801).

While in medical school, he made original studies of the eye and later developed what is now known as the three-color theory of vision. He also did research in physiology. Young also turned to optics and showed that many of [NEWTON's] experiments with light could be explained in terms of a simple wave theory of light. This conclusion was strongly attacked by some scientists in England who defended Newton.

COLORS, PRIMARY, (OF LIGHT) - (1775)

Even before [NEWTON's] famous prism experiment in 1666, man has long pondered the nature of color. After Newton, it was discovered that sunlight actually contains a continuous spectrum of colors, not just the seven distinct colors that Newton identified. Modern scientists however have recognized only three primary colors as follows:

Mayer (1775): - red, yellow and blue.

Thomas Young (1801): - red, green and violet

Clerk Maxwell (1860): - red, green and blue

Today we consider red, green and blue to be the three primary colors in light. These are the three colors from which all other colors may be 'mixed'. White light is a mixture of equal parts of all three primary colors. Secondary colors in light are formed when any two primary colors are mixed together. The secondary colors are as follows:

red and blue = magenta
red and green = yellow
blue and green = cyan

Complementary colors are any two colors when mixed together provide 'white light" Examples of complementary colors are as follows:

magenta and green = white
yellow and blue = white
cyan and red = white

The color sensation of 'black' is produced by the absence of light.

TURNER, JOSEPH MALLORD WILLIAM - (London, 1775 - 1851)

Turner was an English landscape painter, renowned for his vibrant and dramatic treatment of natural light and atmospheric effects. He viewed the world through the medium of light and sought to explain light and its action upon the physical nature of things by his own theoretical ideas. Turner became one of the first to give art a new intellectual basis whose only goal was objective expression of the subjective experience.

ETIENNE, LOUIS MALUS - (1775 - 1812)

Louis Etienne was a French physicist who discovered that light when reflected becomes partially plane polarized, i.e. its rays vibrate in the same plane. He published a paper in 1809 on his discovery, and a memoir in 1810 on the theory of double refraction of light in crystals. See also: [POLARIZATION] and [POLAROID].

DAVY, SIR HUMPHRY - (1778-1829)

Davy was a renowned British chemist, best known for his experiments in electrochemistry and for his invention of a minor's safety lamp. Davy was born on December 17, 1778, in Cornwall, England. He experimented with the properties of gases during which he discovered the anesthetic effects of nitrous oxide. (laughing gas). Davy was appointed assistant lecturer in chemistry at the newly founded Royal Institution in London in 1801 and the following year became professor of chemistry there.

Davy is also given credit for inventing the electric arc. The electric arc revolutionized lighting at the time, as now there was a powerful 'clean' source of light available as an alternative to oil or gas. The high (relative) light output made the electric arc lamp particularly suited to both theatre and street lighting applications. See also: [ELECTRIC ARC].

FRESNEL, AUGUSTIN JEAN - (1788 - 1827)

Fresnel (pronounced (Fr'nel) was an engineer of bridges and roads for the French government. In his spare time (as a physicist) he carried out extensive experimental and theoretical work in optics. Fresnel developed a comprehensive wave model of light that successfully accounted for; reflection, refraction, interference, and polarization. He also designed a lens system for lighthouses that is still in use today. The fresnel lens is also used in the modern 'fresnel spotlight', a common fixture with an adjustable beam spread, used for stage and television lighting applications.

DAGUERRE, LOUIS JACQUES MANDE - (1789 - 1851)

Daguerre was a French scene painter known for his illusionistic stage sets. He was also the inventor (with C.M. Bouton), of the diorama. The diorama was a three dimensional setting usually melded with two dimensional painted backgrounds and realistic lighting effects. Today dioramas are commonly used by museums for display or exhibit applications.

Daguerre, working, with J. Nicephore Niepce, developed the daguerreotype, a photograph formed on a copper plate coated with silver and treated with iodine vapor. This was the first practical photograph.

BETTY LAMP (& BETSY LAMP) - (1790)

The simple oil lamp, consisting of an open (then later enclosed) saucer or pan filled with animal or vegetable fat and some form of porous wick, remained virtually unchanged for several millennia.

Early American lamps, (originating from Europe) included tin and iron versions of this simple oil lamp. An improved oil lamp, using an integral wick support caused the drip to run back into the reservoir and made it a 'better lamp'. This improved lamp became known to the American colonists as the 'betty lamp' and the 'betsy lamp'. It was simply a metal variation, of the early Greek and Roman oil reservoir lamp, once made from pottery.

As defined by Charles L. Woodside in "Early American Lamps", they usually were of an 'open' type, although some of the later betty lamps were covered but not spill proof. The lamps of this period burned any grease or oil available and were apt to be smelly, messy, and demanding of constant attention". Examples of the betsy lamp date from about 1790.

Additional Reading: Lighting in America, Lawrence Cook, 1977.

FIRST - GAS LIGHTING - (1792)

- See: [MURDOCK, WILLIAM]

1800

19TH CENTURY STAGE LIGHTING - (1800's)

At the beginning of the 19th Century stages were illuminated by [ARGAND] oil burners. They were provided as footlights, stage side lights and by overhead chandeliers. For stage use, the glass chimney was often made from colored glass. During the Century, [GAS LIGHTING] developed and flourished. Other sources such as the [ELECTRIC ARC] lamp and the [LIME LIGHT] were also developed and put to use on stage.

However, up until this point in time, all lighting devices had one major drawback - they all were flame sources. They had to burn right side up, be supplied with air, protected from objects that might catch fire, and be protected from drafts. Also, they were difficult to start, and they were a source of pollution.

Additional Reading: Legge, Tabs September 1968.

INFRARED - (c 1800)

About 1800, an astronomer, William Herschel discovered that the spectrum of the sun contains more than invisible colors. Using a prism to split the sun into a spectrum, he experimented with a thermometer, and measured the temperature of each color. He found that the highest temperature reading came from the region beyond the red, where no color could be seen. Herschel had discovered that infrared energy is a form of invisible light.

Energy, with a greater wavelength than 0.0008 millimeters fall in the range of the infrared range. We experience these rays as heat. The longer such heat rays are, the more insensitive to them, our eyes become.

ULTRAVIOLET LIGHT (UV) - (1801)

The 'dark portion' of the solar spectrum (adjacent to violet light) was discovered in 1801 by the German physicist Johann Wilhelm Ritter and was named 'ultraviolet' radiation.

Today we classify UV radiation as follows:

UV-A (320-400 nanometers) - which is adjacent to visible light, is often referred to as near-UV or black light. This band is the least energetic UV radiation.

UV-B (290-320 nanometers) - lies in the middle spectrum. It is commonly known as erythemal UV and is the band that converts ergosterol in the skin to vitamin D.

UV-C (160-290 nanometers) - is the shortest UV wavelengths, and because of its effectiveness of killing one cell organisms, is called germicidal UV. The shorter wavelengths produce ozone in air (oxygen).

See also: [SUNLIGHT AND CANCER] - (a 1990)

WINDSOR, FREDERICK ALBERT - (1804)

In 1804 Frederick Albert Windsor, a German entrepreneur, demonstrated and lectured on gas light at the Lyceum Theatre in London. His main interest in gas was for street lighting. Windsor acquired a house in Pall Mall, London and on June 4th, 1807, the King's birthday, he exhibited lights and a gas-lit transparency along the walls. In 1809-10, Windsor established the first public gas company, The Gas Light and Coke Company, which remained in existence until the company was nationalized in 1948.

ELECTRIC ARC LIGHT/ CARBON ARC LIGHT - (1809)

In 1809, SIR HUMPHREY DAVY first demonstrated the electric carbon arc at the Royal Institution in London. The electric arc was also used for lighting at the Paris Opera. At that time and until about 1860, the only source of electrical power came from batteries. After the electric generator developed sufficiently, there was a surge of activity from 1878 onwards. (B.S.M.)

Electric arc lamps were introduced outside the Paris Opera in 1877. These were [JABLOCHKOFF] candles in which two parallel sticks of carbon where separated by an insulator which was melted slowly away by the arch thus self-feeding the two carbons.

By 1884 there were 90,000 electric arc lamps burning by night in the USA, where development was on a greater scale than elsewhere.

The principal of the electric arc is still used today by many older followspots and film projectors, used in entertainment facilities around the world. Modern followspots and projectors now tend to rely on a High Intensity Discharge, (Xenon, CSI, HTI, etc.) lamps, instead. See also: [FIRST - FOLLOWSPOT]

BUNSEN, ROBERT WILHELM - (1811 - 1899)

In 1855, Bunsen (German chemist) was given credit for inventing the Bunsen Burner. The burner is a short, vertical tube of metal connected to a gas source and perforated at the bottom to admit air. The flow of air is controlled by an adjustable collar on the tube. He also was a co-inventor of the [SPECTROSCOPE] along with the German physicist Gustav Robert Kirchhoff.

Contrary to popular belief, he had little to do with the invention of the Bunsen burner, a burner used in scientific laboratories. Although Bunsen popularized the device, credit for its design should go to the British chemist and physics Michael [FARADAY]. Among Bunsen's inventions are the ice calorimeter, a filter pump, and the zinc-carbon electric cell. He used the cell to produce an [ELECTRIC ARC] light and invented the photometer to measure its luminosity.

ANGSTROM, ANDRES JONS - (1814 - 1874)

(Also: ANGSTROM) - Angstrom was a Swiss (Swedish?) physicist known for his study of light. He studied spectrum analysis and mapped the sun's spectrum. He discovered hydrogen in the solar atmosphere and was the first to examine the spectrum of the [AURORA BOREALIS]. The unit of wavelength, the angstrom, was named after him.

GAS LIGHTING - ENGLAND - (1814)

The first general use of gas street lighting took place in London in 1814. By 1823 nearly 40,000 lamps had been installed in 215 miles of London streets.

It was the introduction of gas lighting to the theatre that began the first real advance in theatre lighting. Gas was manageable and controllable. Centralized remote control systems were developed, usually in wings, backstage. The 'gas plate' contained control valves between the main gas supply and each gas lighting 'circuit', and allowed the footlights, wing lights, etc. to be dimmed, brightened or extinguished at will.

By 1817, Covent Garden, Drury Lane and the Lyceum were all lit by gas. The last London theatre to adapt to gas was the Haymarket, where candles and oil lamps were used until April 1843.

GAS LIGHTING - AMERICA - (1816)

Gas lighting was introduced to the American theatre in 1816 at the Chestnut Street Theater in Philadelphia. In 1926 the Bowery Theater was the first in New York, to be lighted by gas. The theatre burned nine times before it was demolished in 1930. There was no gas lighting in Chicago theatres, prior to 1850, when the first municipal gas works were constructed.

As municipal gas companies did not exist throughout the country, each theatre had to manufacture their own supply of gas. Although gas had many advantages over oil lamps and candles, it is said that several hundred theatres burned down in Europe and America from the use of gas lighting.

By 1817, the development of gas production, storage and metering was virtually complete. By 1860, gas jets were lighted with electric sparks and most fixtures had glass chimneys.

Additional Reading: Theatre Design & Technology, May 1969. (& photos)

HELMHOLTZ, HERMAN - (1821 - 1894)

Helmholtz, (helm'holts) Germany, was a pioneer of physiological optics and acoustics and he made fundamental contributions to the physiology of the senses of sight and hearing. He also studied electricity, magnetism and higher mathematics.

Additional Reading: Microsoft Encarta 1997 Encyclopedia

CON EDISON - (1823)

Con Edison, which traces the corporate lineage of its electric company back to Edison, has been part of New York City since 1823, when its founding corporate ancestor, the New York Gas Light Company, was chartered. Con Edison, as we know it today, is the result of the acquisitions, dissolutions, and mergers of more than 170 individual companies. By far, the most historically significant of those companies was the Edison Electric Illuminating Company of New York, formed by Thomas [EDISON] in 1880.

PHOTOGRAPHY, MODERN - (1826)

After the early work of Schultz, Wedgewood, Davy and Herschel, it was Joseph Niepce who made the next major advancement in the field of photography.

In 1826, Joseph Nicephore Niepce, a French lithographer used a small camera obscura to capture an eight hour exposure on a sensitized sheet of pewter. Although the results would have been quite crude, Niepce had brought together the concept of the camera obscura with the ability to form an image through a chemical reaction triggered by light.

In 1829 Niepce began to work with Louis Daguerre, a Parisian painter and scenic designer for the Paris stage. Niepce died in 1833. Daguerre eventually succeeded in developing the first practical photograph - the daguerreotype in 1839. A lens was added to the camera obscura about this time resulting in sharper images using less light. The Daguerreotype Camera soon followed. See also: [DAGUERRE].

In 1840 William Henry Fox Talbot developed a paper 'film', treated with silver chloride crystals. When exposed and chemically treated, the paper would produce a negative image. This negative image could be pressed against a similarly treated paper and exposed to sunlight to make a positive print. Any number of prints could be made from a single negative. Until this time, the image was formed completely in the camera.

In 1847, Claude Niepce (a cousin of Joseph Niepce) invented the photographic glass plate. The light sensitive emulsion was applied directly to the glass plate, yielding a negative far superior in image quality, to that of previous methods.

In 1881 the halftone printing process was developed making possible the reproduction of photographs in magazines and books.

In 1884 Eastman produced a celluloid film that both produced high quality images and could be rolled into a compact spool. After development, the negative image could be printed directly on to sensitized paper. See also: [EASTMAN].

Eastman coined the word 'Kodak' and in 1888 started to market a compact hand held box camera, using his new film.

In 1861 James Clerk Maxwell demonstrated the first color photographs. He exposed the same plate three times through filters of red, green and blue. See also: [MAXWELL].

DRUMMOND, THOMAS - LIMELIGHT - (1826)

The limelight was invented an Englishman, Thomas Drummond, about 1826. He discovered that a piece of lime glowed brilliantly when heated by an oxygen and hydrogen flame. When placed at the focus of a parabolic reflector, it allowed him to signal from Antrim to Ben Lomond Scotland, a distance of 95 miles. Details were first published in his ' Philosphical Transactions' in 1826, in which he described how he ad achieved a light 83 times brighter than the brightest flame from an Argand burner.

It wasn't until about 1856 that the first theatrical use seems to be made at the Princesses Theatre, London, where a lens was placed in front of a limelight to give a spotlight. By 1860 limelight was in common use, and was useful for the provision of sunlight moonlight, or for use as a followspot. In its popular form, for magic lanterns and for stage lighting, coal gas was substituted for hydrogen. The limelight had an exceptionally long run in the theatre and was still in regular use in London theatres until about 1910.

FRICTION MATCH - (1827)

The friction match was invented in England in 1827, by a druggist, John Walker, and were known as 'lucifers'. Until that time, all lamps and candles had to be lighted from either another flame or from fire struck with flint and steel. Now man had the additional freedom to produce fire, anywhere, on demand.

MAXWELL, JAMES CLERK - (1831 - 1879)

Maxwell was a Scottish physicist born in Edinburgh. Like Newton before him, Maxwell made contributions of fundamental importance to many branches of physics. In 1873 he found that magnetism and electricity were related and he formed a single unified theory of electromagnetism Maxwell realized that light was electromagnetic radiation and as such must consist of a wave with two components, an electric field and a magnetic field that vibrate at right angles to each other. Maxwell also developed a quantitative theory of color vision - and even produced one of the first (if not the first) color photographs.

FARADAY MICHAEL - (1832)

In 1832, Michael Faraday (England) announced that he had converted magnetism into electricity. He had sent a current through a coil of wires, creating a magnetic field which induced a momentary current in a second coil. In America Joseph Henry affirmed that he had done much the same thing at about one year earlier. The discovery of electromagnetic induction led to the development of electric motors, generators and dynamos.

LANGLEY, SAMUEL PIERPONT - (1834 - 1906)

An instrument with which heat rays can be measured with the utmost precision in the bolometer, so named because in Greek 'bole' is equivalent to 'ray'. Bolometers have been known for a comparatively long time. The first instrument of the kind was a 'resistance' bridge invented by the American Samuel Pierpont Langley (1834-1906), consisted of four fine, blackened iron wires. They formed the branches of a very sensitive measuring instrument that operates on the zero principle. When no current is flowing through the instrument, the needle of a galvanometer connected to it shows no deflection. In Langley's bridge, two of the wires were connected to a small battery, and the other two to the terminals of a sensitive galvanometer. When a beam of light was directed at one of the wires through a narrow slit, the wire was heated. This altered the electrical resistance and the electrical equilibrium on the bridge was thereby upset, so that a current was set up in one arm of the bridge and deflected the needle of the galvanometer.

Also see: [INFRARED].

MONET, CLAUDE - (1840 - 1926)

Monet was a French landscape painter and one of the founders of impressionism. Monet is also considered to be one of the leading landscape artists of all time. Later in his career he devoted himself to painting the changes of light and atmosphere caused by different seasons and different times of day. He broke light down into its component colors much as does a prism. He repeatedly painted such subjects as haystacks, Rouen Cathedral, and the great lyrical series of water lilies (1899 & 1904-1925) in his garden at Giverny.

EDISON, THOMAS ALVA - (1847 - 1931)

Thomas Alva Edison was born at Milan, Ohio, and spent most of his boyhood at Port Huron, Michigan. His first love was chemistry. In 1877 Thomas Edison became interested and experimented with electric lighting but abandoned his work later that year due to a lack of funds and other pending developments. In 1878, his friend Grosvenor P. Lowrey, a patent attorney helped raise $300,000 from investors to back Edison's experiments. On October 15, 1878, the Edison Electric Light Company was incorporated. The objectives of the company were: "to own, manufacturer, operate and license the use of various apparatus used in producing light, heat or power by electricity."

Edison patented more than 1000 inventions. Besides the incandescent lamp, Edison is given credit for inventing a system of electric generation, the phonograph, and the kinetoscope (motion picture camera) and the motion picture projector (the Vitascope patented in 1896).

"Genius is ninety-nine percent perspiration and one percent inspiration" - (Thomas Edison).

WAGNER, RICHARD - (1849)

Wagner showed great interest in the operation of the theatre and created a demand, for extensive technical elements. He was concerned with staging, scenic and lighting effects, and to a limited degree, theatre architecture. In 1849 he published his conceptions of a new art, under the title of 'The Work of Art of The Future'.

SPEED OF LIGHT - (1849)

A ray of light directed along the 25,000 miles of the earth's equator would return to its starting point in 0.13 seconds. In one second it would have covered the distance seven or eight times. By comparison, sound, which travels at only 1,086 feet per second, would require 33.3 hours, while an express train with a speed of sixty miles per hour would need 17 days, assuming its journey were unbroken.

Speed of Light: All forms or radiant energy are transmitted at the same speed, in a vacuum. After early calculations by Roemer and British astronomer James Bradely, the French physicist Armand Fizeau (30), in 1849 established the speed of light at approximately 186,300 miles (300,000 kilometers) per second.

In 1968, in accordance with recommendations from the International Astronomical Union (Hamburg) the speed of light was established at 299,792.5 kilometers per second or 186,282.3976 statute miles per second. Solar parallax, 8".794; constant of nutation, 9".210 and constant of aberration, 20".496.

Light travels at different speeds in different media. In the vacuum of space, light travels at approximately 186,000 miles per second. It is slower in air and still slower in glass.

And Finally:

Nothing is faster than the speed of light... To prove this to yourself, try opening the refrigerator door before the light comes on. (Anon.)

SPECTROSCOPE - (c 1850)

The credit for investigating the light of flames (after Agricola and [MELVILL]) belongs to two Heidelberg professors; the physicist Gustav Robert Kirchoff (1824-1887) and the chemist Robert Wilhelm [BUNSEN] (1811-1899). At first they made use of a prism only. When the light of flames so colored was passed through a prism, sharply defined single lines in unmistakable colors appeared. To be able to observe these better, the two scientists constructed a simple but highly effective and sensitive instrument. The whole apparatus was rigged up from an empty cigar box, a prism, and parts of an old, discarded telescope. It was the first spectroscope, a little thing on three legs like a microscope, and provided with an eye-slit. Inside it the light rays made their way through lenses and the prism. With this instrument, it was possible to study the spectra of red-hot bodies and gases, much more accurately than with a prism alone.

PROFESSOR PEPPER - (c 1850)

During the mid-1800's an illusion was described and illustrated, that later became know as 'Pepper's Ghost'. The illusion consisted of the merging of live actors with reflected (ghost) images of hidden backgrounds or other actors. The technique had several variations however all used an angled sheet of glass, separating the audience from the illusion.

Dr. John Henry Pepper was Director and Professor of Chemistry at the Royal Polytechnic Institution, London, (founded in 1838). Pepper presented the illusion in the form of 'The Knight Watching his Armour'. Others with patents for the illusion include Munro in 1863 and Maurice in 1865.

The illusion is still used today in many a 'Haunted Castle' and themed exhibits and dark rides throughout the world.

KEROSENE LAMP - (1853)

The kerosene lamp was introduced in Germany in 1853. Kerosene was distilled from petroleum obtained from oil shale, found in mines. By 1856 Kerosene was used to light homes in New York (gas came to that city in 1864.)

EASTMAN, GEORGE - (1854 - 1932)

Eastman (USA) invented roll film and the name 'Kodak'.

In 1885 American inventor George Eastman marketed his first box camera. It sold for $25.00, a considerable sum in those days. The Kodak camera, the first camera designed to use roll film, came with the film already installed. After the purchaser took 100 pictures, the camera had to be returned to the factory, where the film was removed and processed and new film was installed.

FIRST - FOLLOWSPOT SPOTLIGHT - (c 1856)

The followspot is simply a high power spotlight mounted on a stand. An operator (or stagehand) controls the lamp and is able to pan and tilt the spotlight, following an actor anywhere on stage. Although it is not certain when the concept of the followspot was developed and first used for theatrical applications there is documented evidence that a limelight with a lens was used in a London theatre, about 1856.

Today, the followspot fixture is still commonly used, for theatre, dance, opera and other entertainment events. Over the decades, the followspot has evolved from the [LIME LIGHT] to the [ELECTRIC ARC] to the modern Xenon units of today. Leading manufacturers of followspot products include: [STRONG] [ALTMAN], Lycian and Phoebus.

THOMPSON, SIR JOSEPH - (1856 -1940)

Joseph J. Thompson, (British) investigated the properties of cathode rays under the influence of magnetism and electrically charged plates. He constructed a specially designed 'cathode ray tube' and identified the radiation and the particle we now call the 'electron'. At the age of twenty-four he was made a Fellow of the Royal Society, and a year later was elected to professorship at Cambridge. In 1906 he received the Nobel Prize for physics, and he was knighted in 1908.

HERTZ, HEINRICH RUDOLF - (1857 - 1894)

Hertz was a German physicist who produced and studied electromagnetic waves (radio waves), which he showed are long transverse waves that travel at the speed of light. Further he showed that these waves can be reflected and refracted, like light. The unit of frequency, the hertz, is named after him.

PLANCK, MAX - (1858 - 1947)

Max Planck (German), derived quantum theory from study of black body radiation. This was a modern form of the corpuscular theory [NEWTON], based on the following premises: That energy is emitted and absorbed in discrete quanta (photons) and that the magnitude of each quantum may be calculated in accordance with Planck's constant.

MUNSELL, ALBERT H. - (1858 - 1918)

Albert H. Munsell, (American) published his first edition of "A Color Notation" in 1905. This was followed by the production of his first color chart. During the next ten years. he prepared a series of color charts which he later assembled into the "Munsell Color Atlas".

Today, the Munsell System, is the most widely accepted method of accurately describing object color. (assumes a normal observer, daylight illumination and observation of the color samples against a gray to white background). In the Munsell System, colors are specified in terms of three (3) attributes: hue, value and chroma.

CANDLEPOWER - (1860)

In 1860, one of the basic lighting measurements, the candlepower, was established using a Spermaceti candle, of a specific weight and burning at a particular rate, as the basis.

APPIA, ADOLPHE - (1862 - 1928)

Appia was a Swiss theorist of stage lighting and decor. His use of light and shade when staging [WAGNER'S] operas revolutionized modern scene design and stage lighting. He was also one of the first to realize the great potential of light in the theatre, once electricity had been introduced. Appia rebelled against naturalism and defined the stage in terms of time and space and suggested the use of light to create mood and composition.

He called the familiar light of his time (from borderlights and footlights) general illumination (Helligkeit). According to Appia, this type of light was useful, perhaps, but inadequate, there must be a new kind of light, a 'form revealing light' (gestaltendes Licht) to give objects on stage their natural three-dimensional quality - there must be 'living light' for living people.

Additional Reading: Norman Marshall, Tabs, September 1969.

KLIEGL, JOHN H. - (1869 - 1959)

John Kliegl - was one of the founders of the American lighting manufacturer [KLIEGL BROTHERS].

KLIEGL, ANTON - (1872 - 1927)

Anton Kliegl - was one of the founders of the American lighting manufacturer [KLIEGL BROTHERS].

CRAIG, EDWARD GORDON - (1872 - 1966)

Edward Craig (British) began his career as an actor but unable to work freely in England moved to the Continent. He spent most of his life battling against what he considered the egotism and stupidity of the actor, the inadequacy of the producer, the crudity of the usual scene designer. He revolted against the conventions of the theatre and demanded the use of light as scenery and compositional elements with the play.

PHOTOGRAPHY, MOTION PICTURES - EARLY - (1872)

For centuries, adults and children alike have been amused by toys that utilized the persistence of vision to present the appearance of a moving picture. One early device was the Zoetrope, a revolving drum with pictures inside. Spin the drum and when viewed from the right angle, the pictures would blend together into a moving picture.

Eadweard Maybridge in 1872 snapped 12 consecutive photos of a horse galloping. His technique for talking sequential photos with the phenomenon of the persistence of vision provided the basis for motion pictures. Eastman's celluloid film which could be rolled into a cylinder, made it practical.

REINHARDT, MAX - (1873 - 1943)

Max Reinhardt was the first director to make an international reputation. He dominated the theatre of Central Europe for more than twenty-five years, refusing to be confined to the proscenium arch, and setting his plays in a ballroom, a circus, a cathedral square, or an exhibition hall, anywhere in fact, where he could find space for his grandiose projects. The most memorable of them was "The Miracle", a vast spectacle whose crowds he manipulated with ease. His extensive travels brought him into prominence everywhere. He finally settled in the United States in 1933.

Reinhardt also applied the principals of [APPIA] and [CRAIG] and used light as a dramatic medium.

ELECTRIC LIGHTING

FIRST - ELECTRIC FILAMENT (INCANDESCENT) LAMP - (1874)

Although Edison did not invent the electric filament lamp, he did however turn theory into practicable form and was one of the first to successfully market incandescent lighting. We must not over look the work done before him by [SWAN] (Britain), Cruto, Gobel, Farmer, Maxim, Lane-Fox, Sawyer, and Mann, to name only a few. The first Canadian patent covering an incandescent lamp was submitted by Henry Woodward and Matthew Evans, dated July 24, 1874 - approximately five years before the development of the Edison lamp. It was probably however, the German chemist Herman Sprengel who pioneered the vacuum light bulb in 1865.

Reference: for further information consult the MIT studies of invention publication, authorized by Arthur A. Bright, entitled "The Electric Lamp Industry".

TELEVISION, THE CONCEPT - (1875)

The first electric TV system was proposed by George Carey of Boston in 1875, and was based on selenium cells.

JABLOCHKOFF, PAUL - (1878)

By 1878, Paul Jablochkoff had developed an arc in the form of an electric candle. It was made of two carbon rods, side by side, with an insulating material placed between them, that burned away at the same rate as the carbons. In 1879 a theatre in France was equipped with some of them, but the development of the incandescent lamp prevented them from appearing in general use.

EDISON LAMP - (1879)

Edison's first successful lamp used carbonized cotton thread as a filament, installed in a glass bulb, with all air evacuated. On the afternoon of October 21, 1879, Edison's prototype had lasted 45 hours. The next day Edison began to experiment using cardboard as a filament. The cardboard filament was even more successful, and in a couple of months, production of his lamps had increased. On New Year's Eve, December 31, 1879, Edison gave his first public demonstration of his new invention, at Menlo Park, New Jersey. Special trains were run on the Pennsylvania Railroad to accommodate the masses of visitors. About 100 cardboard filament lamps were used in this demonstration, lighting the streets, the laboratory, and the station at Menlo Park. Each lamp was rated at 16 candlepower and consumed about 100 watts. (Average life was about 100 Hrs.)

In 1880 Edison experimented with other materials for filaments, including wood, grasses, hair and bamboo. Of the over 6000 specimens tested by his laboratory, bamboo, became commonly used for filaments.

In 1880, on January 17, Patent number 223,898 was issued to Edison for the T.A. Edison Electric Lamp.

In 1881, two years after the first incandescent lamp left Edison's workshop, the steamship 'Columbia' was fitted with a thousand of them. Within another two years, there were over 300 electric power stations in existence, feeding over 70,000 incandescent lamps, each with an average life of 100 hours.

See also: [FIRST - ELECTRIC FILAMENT LAMP] - (1874)

SWAN LAMP - (1879)

Along with [EDISON], (and others) Joseph Swan, is also credited with inventing the incandescent lamp. Swan demonstrated a carbon filament lamp to about 700 people in Newcastle-upon-Tyne on February 5, 1879.

Swan's development of the incandescent lamp was reported in the Oct. 29th, 1880 issue of "Engineering", which quotes him as follows: (SWAN) "Electric lighting by incandescence is just as simple as arc lighting is difficult, all that is required is a material which is not a very good conductor of electricity, highly infusible and which can be formed into a wire or lamina, and is neither combustible in air, or if combustible, does not undergo changes in a vacuum".

The first premises to be lighted by the new Swan lamp were those of Sir William Armstrong at Cragside near Newcastle in December 1880.

See also: [FIRST - ELECTRIC FILAMENT LAMP] - (1874)

PHOTOELECTRIC CELL - See: [FIRST - PHOTOCELL] - (1880)

FIRST - PHOTOCELL - (1880)

The first means for converting sunlight directly into electrical energy date back to 1880. In that year the first selenium cells were constructed by Charles Summer Tainter (American) The photoelectric cell, as it called, has been improved in recent years, however the typical output of a single cell is still not be enough to light a small flashlight bulb (lamp). Photo cells are also used in light meters and in other optical measurement equipment.

PHOTOPHONE - (1880)

In 1880, The Photophone was developed by Alexander Graham Bell. This device used a mirror to transmit a speakers voice over a beam of reflected sunlight. The transmitter mirror was modulated by the speakers voice. The receiver used a rod of selenium, a metal whose resistance changes with the intensity of light falling on it. Electricity turned out to be more reliable than sunlight and Bell turned his efforts to the telephone. Bell apparently wanted to name his second daughter after the Photophone as she was born a few days after his first successful demonstration of the device in February 1880. Apparently Mrs. Bell did not share his enthusiasm.

Modern day versions of the Photophone even exist today. From time to time many of the popular electronics magazines provide construction projects for 'light beam communicators'.

LIGHT PIPE - (1880)

In 1880, William Wheeler of Concord, Massachusetts, applied for and received a patent, on light pipes. His idea was to use pipes with reflective inner surfaces to direct light from a source at one end, along the length of the pipe. Concord's prototype was not very efficient and most of the light was absorbed by the mirrors.

The light pipe uses the principal of 'total internal reflectance'. This principal was noted about ten years earlier by John Tyndal, when he shone a light at a spout of water as it gushed out of a tank. The water fell in an arc and the light went with it. The outer edge of the water spout was acting as a mirror, reflecting the light that reached it back toward the interior of the spout. Total internal reflection only works when light strikes the air/water boundary at a small glancing angle. At larger angles the light passes through, the water like transparent glass.

The principal of total internal reflection is used by the modern light pipe and by fiber optics.

See also: [TIR SYSTEMS].
See also: [FIBER OPTICS].

CARTE, RICHARD D'OYLEY - (1881)

Richard D'Oyley (often: D'oyly) Carte, was the enterprising manager of the new Savoy Theatre in London. In 1881 he opened the theatre and advertised that the Savoy was the first public building lighted 'entirely' by electricity. In fact, there were a total of 1158 of the new Swan lamps, used to light the auditorium, the dressing rooms, the corridors and the stage. The electrical and dimmer system was by Siemens Brothers and Company, one of the early pioneers in stage lighting control systems. There were six (6) dimmers in all.

An article published in 'Engineering, March 3, 1882' reported: "In an artistic and scenic point of view nothing could be more completely successful than the present lighting of the Savoy Theatre the illumination is brilliant without being dazzling, and while being slightly whiter than gas, the accusation of "ghastliness," so often urged against the light of the electric arc, can in no way be applied. In addition to this the light is absolutely steady, and thanks to the enterprise of Mr. D'Oyley Carte, it is now possible for the first time in history of the modern theatre to sit for a whole evening and enjoy a dramatic performance in a cool and pure atmosphere".

At the same time, the Grand Opera in Paris installed the Swan lamp.

LANGMUIR, IRVING - (1881 - 1957)

Irving Langmuir (General Electric Research Lab.) pioneered the development of the first gas-filled electric lamp, at atmospheric pressure. He demonstrated that it was not the vacuum in the bulb that allowed the filament to burn for a long time. Instead he showed that by simply adding nitrogen gas, evaporation of the filament was slowed, prolonging the life of the lamp. Later, Langmuir later substituted argon for nitrogen. See also: [GAS FILLED LAMP] - (1913)

TELEVISION, EARLY - (1884)

Some of the earliest work on television began in 1884, when the German engineer Paul Nipkow designed the first true television mechanism. In front of a brightly lit picture, he placed a scanning disk (called a Nipkow disk) with a spiral pattern of holes punched in it. As the disk revolved, the first hole would cross the picture at the top. The second hole would passed across the picture a little lower down, the third hole still, and so on. With each complete revolution of the disk, all parts of the picture would be briefly exposed in turn. The disk revolved quickly, accomplishing the scanning within one fifteenth of a second. Similar disks rotated in the camera and receiver. Light passing through these disks created crude television images.

Nipkow's mechanical scanner was used from 1923 to 1925 in experimental television systems developed in the United States by the inventor Charles F. Jenkins, and in England by the inventor John L. Bard. The pictures were crude but recognizable. The receiver also used a Nipkow disk placed in front of a lamp whose brightness was controlled from the light-sensitive tube behind the disk in the transmitter. In 1926 Baird demonstrated a system that used a 30-hole Nipkow disk.

GAS MANTLE / WELSBACH - (1885)

Some improvement in gas lighting was made over the years by the development of new types of burners. It was not, however until Welsbach introduced the gas mantle in 1885 that gas lighting was greatly improved. A gas mantle is made from a small knitted bag, dipped into chemical and then dried. When a new mantle is tied to a gas jet and the gas is lighted, the knitted material will burn away leaving a fragile shell of chemicals which glow brightly in the heat of the gas flame. Many 'gasoline' type and camper lanterns today still use mantles.

Credit for the first metal filament lamp also goes to Welsbach. He developed a rather efficient lamp with a filament of the rare metal Osmium in 1905. However, this metal was even more rare and expensive than platinum and the lamps were not highly successful.

WESTINGHOUSE - (1886)

Westinghouse was founded in 1886 by George Westinghouse. Westinghouse received more than 400 patents for his many inventions, including the air brake (1882) and a method of transmitting electrical power. He also refined the transformer, providing a practical method of distributing A.C. power over a large network. Edison at the time rejected alternating current in favor of direct current.

Westinghouse has grown to be a world wide supplier of electrical components, appliances and lamps. In 1995 Westinghouse purchased CBS for $5 Billion (US), just one day after the Walt Disney Co. announced its purchase of Capital Cities/ABC Inc.

DUBOIS, RAPHAEL - (1887)

Dubois, in 1887 demonstrated the existence of a specific compound he called luciferin, which interacts with an enzyme, luciferase and oxygen to produce light. See also: [BIOLUMINESCENCE].

FINSEN, N.R. - (1889)

It was in 1889 than Niels Ryberg Finsen, a Dane, discovered that the ultraviolet component of natural sunlight, in fact, was responsible for sunburn. Finsen received the Nobel Prize in 1903 (04?) for his pioneering work - which led to widespread study of UV and its effects. Finsen investigated the photo biological effects of sunlight and even had an engineer commissioned to build a large [ELECTRIC ARC] lamp so that he could further experiment with the effects of artificial sunlight for therapeutic purposes. The arc lamp operated at a current of twenty-five amperes and was rich in ultraviolet rays. {1ST SUNLAMP}

LEONARD, HARRY WARD - (1889)

Inventor, Ward Leonard worked with Thomas [EDISON] to introduce the central station electrical system concept to cities in America. Leonard in 1892 received a patent for an electric elevator.

WILFRED, THOMAS - (1889 - 1968)

Thomas Wilfred, was born in Nestvad, Denmark. Between 1905 and 1911 he studied music and art in Copenhagen, Paris and London - and became a singer of old songs. He began to experiment with color mixing and projection and developed a device called the 'Clavilux' (1919). It consisted of spot and flood lights, rheostats, screens, filters and prisms, all controlled by an elaborate control console.

In 1916 he came to the United States and continued his career as a singer in order to gather funds for his experiments in the use of light as an art medium. Wilfred debuted his Clavilux at the Neighborhood Playhouse in New York in 1922. Between 1922-1929 he made tours and gave concerts in the USA and Canada. In 1925 he appeared in Paris, London and Copenhagen. Later he founded the Art Institute of Light in West Nyack, New York. He continued lecturing, creating and writing, until his death in 1968.

GENERAL ELECTRIC COMPANY - (1892)

Created in 1892 through a merger of Edison's General Electric with Thomson-Houston Electric Co. The Edison name was eliminated because it had lost prestige since an electric chair fiasco two years earlier. Edison still insisted that DC not AC current should be used.

Today, General Electric has grown to be one of the largest suppliers of electrical components, appliances, equipment and machinery, in the world. The company is a major manufacturer of lamps (light bulbs) for all applications. In 1985 General Electric purchased RCA and its National Broadcasting Co. for $6.3 billion US dollars.

http://www.ge.com

INTERNATIONAL ASSOCIATION OF THEATRICAL STAGE EMPLOYEES - (1893)

I.A.T.S.E. (IATSE) - is a professional union with more than 75,000 members in over 500 locals, throughout the United States and Canada. The 'I.A.' serves the technical needs of most professional stage productions, arena shows and films, throughout North America.

ARGON - (1894)

Argon, (Ar), from argon, or inactive, was discovered in 1894 by Scottish chemist William Ramsay, who removes from air, various known gases including nitrogen, oxygen, and carbon dioxide and find an inert gas remains. The most abundant of noble gases, argon is used in welding applications, as it provides an inert atmosphere, in which welded metals will not burn. It is also the gas that fills most incandescent lamps.

ROENTGEN, WILHELM - (c 1895)

About 1895, Roentgen (German) discovered X-Rays. These rays could penetrate most forms of solid matter, as ordinary light passes through glass. Today his discovery is used for a number of medical diagnostic and therapeutic uses. Roentgen died in 1894 at the early age of 37.

KLIEGL BROTHERS - (1896)

Kliegl Brothers of New York, was founded in 1896 and was one of the oldest if not 'the oldest' stage lighting manufacturer, established in North America. The company made high quality lighting fixtures and control systems for the stage and studio industries. Unfortunately after a turbulent decade of changes, the company ceased operation in the 1990's.

The company was founded by American lighting experts John H. Kliegl (1869-1959) and Anton Kliegl (1872-1927). Kliegl was the manufacturer of the 'Klieglight, a powerful carbon-arc lamp, producing an intense light, used initially for film lighting. It was first introduced in 1911 and then later, the 'Klieglight' was redesigned for the incandescent lamp.

NEON - (1898)

Neon, (Ne), from neos, or new, was discovered in 1898 and is the best known of the inert gases. When an electric current is passed through a minute amount of neon, enclosed in a glass vacuum tube, it glows bright orange red.

Red neon tubes (for display) were first made by Claud in France in 1910. On January 19, 1915, the first patent was issued for a neon sign. In 1925, blue tubes containing argon and mercury first appeared in central London, and sometime later, a green light was produced (simply by enclosing a blue tube in yellow glass). It wasn't until 1933 that fluorescent power coating of neon and mercury discharge tubes produced a whole new range of colors. Neon lamps have almost an indefinite life.

XENON - (1898)

Xenon, (Xe), (pronounced: Zee-non) - from xenos, or stranger, was discovered in 1898. The properties of an electric discharge arc in an atmosphere of xenon gas under high pressure was investigated by Aldington in 1947, and a few limited but important commercial applications followed. Today, the Xenon lamp is used in the commercial [STROBE] (or stroboscopic or high speed flash), as well as a source for projection equipment and followspots.

RADIUM - (1898)

Radium (Ra), from radius, or ray, was discovered in 1898 by Pierre and Marie Curie. It is the sixth rarest of the elements. Radium bromide is often mixed with zinc sulphide to produce a mixture used for luminous watch dials. The radium gives off dangerous radiation which causes the zinc sulphide to glow.

ELECTRICITY - (1899)

Although many early men experimented with electricity, none knew that electricity was atomic in nature. It was the English physicist Joseph John (later Sir Joseph) Thompson, who finally lifted the veil shrouding the phenomenon of electricity. In 1899, he demonstrated that electrons are the carriers of electricity, and, further that each of them carries an elementary quantum of a negative electric charge.

1900

THE 20TH CENTURY - (1900's)

Although the principals of lighting design had been well established during the oil and gas light eras, it wasn't until the development of the incandescent lamp (c1879), that stage lighting could really flourish as an art form. Now for the first time in history it was possible to provide odorless and controlled lighting. The development of lighting fixtures flourished. The gas; striplight, box flood and footlights were redeveloped using the incandescent lamps.

BOX FLOOD / SCOOP / FLOODLIGHT - (1900's)

The 'Box Flood' is an early type of basic stage lighting fixture. Before the widespread use of electricity and the incandescent lamp, candles, oil lamps and gas were all used for stage lighting. Long ago, some brilliant designer enclosed a typical flame source with a cube type housing, having only one open side. Voila, a significant development in lighting fixture design. First, the enclosure would have shielded the source from the audience, increasing visibility and visual comfort. Second, the enclosure would have acted as a crude reflector, helping to direct additional reflected light out of the front opening (or aperture).

Soon after the development of the incandescent lamp, the gas floodlight fixture would have been redesigned to incorporate this new technology. The electric box flood was the most basic of all stage lighting fixtures, as all that was required was a metal box, a socket, a power cord and a lamp. No lens or mechanical controls were required.

The illustration above shows a modern day floodlight fixture, using an electric filament lamp. This fixture, known as the 'Scoop', evolved from the simple box flood and provides a soft wide wash of light. Today modern fixtures often incorporate special asymmetrical reflectors, to help provide an even distribution of light on a vertical surface (backdrop or cyclorama). Some floodlights are also available in multi-cell designs, incorporating 2, 3 or 4 partitioned lamps, each with a different color filter. Modern floodlights typically come in wattages of 300 - 1000 watts.

LINNEBACH PROJECTOR - (c 1900)

Adolf Linnebach was the technical director of the Munich Opera in the early 1900's. He developed a simple projector for background and scenic projection. The projector did not use a lens. Instead, it simply cast a shadow of a silhouette cutout, placed in front of the shielded, light source. The results was a simple, effective image projection, with a soft focus. (Bentham).

The modern Linnebach projector uses a slide size of 24x24 or 36x48 (inches). KLIEGL BROTHERS lighting, claims to have introduced the Linneback projector to the American market in 1922.

FOOTCANDLE (and LUX) - (a 1900)

It was in the early days of electric lighting that users began to ask how much light they needed. The measurement unit of the footcandle was developed as a measure of 'illumination'.

DEFINITION - footcandle, fc: The unit of illuminance when the foot is taken as the unit of length. It is the illumination on a surface, one square foot in area on which there is a uniformity distributed flux of one lumen, or the illumination produced on a surface all points of which are at a distance of one foot from a directionally uniform point source of one [CANDELA]. (REF: IES Lighting Handbook, Ref. Vol. 1981).

The International (metric) unit of illumination is the 'lux'. It is the illumination produced on a surface one square meter in area at a distance of one meter from a uniform point source.

Lux / Footcandle conversions:

    FC  = LUX x .0929  -   Example 1:  500 LUX x .0929 =  46.5 FC
    LUX =  FC x 10.76  -   Example 2:   50 FC  x 10.76 =  538 LUX

Generally you may multiple FC by 10 to obtain LUX - or, divide LUX by 10 to obtain FC.

The recommended illuminance levels for various activities and tasks are published by the Illuminating Engineering Society. Today we know that it is not just the 'amount' of light that affects visibility. Other factors such as contrast and glare are equally important.

The illumination from the sun on the earth's surface can exceed 100,000 LUX, (or 10,000 FC) during a summer day. At night the reflected light from the moon might be as high as 0.2 LUX, (or .002 FC).

SALTWATER DIMMER - (a 1900)

Soon after the development of the electric filament lamp, applications were immediately found in the theatre for this exciting new invention. New lighting fixtures and methods of control were quickly developed and put into use. One early means of lamp 'dimming' was through the use of the salt water dimmer. The dimmer consisted of a tank (or barrel) of salt water brine with a permanent electrode submerged. As a second electrode was slowly raised (or lowered) into the brine, the conductivity between the two electrodes would increase (or decrease) respectively. Lamps connected in series to the dimmer, would be dimmed accordingly. It was not uncommon for a theatre to have a large number of these dimmers and it is said that the heat from the boiling brine would often help to heat the backstage areas. Undoubtedly messy and difficult to operate and maintain, the electric salt water dimmer was soon to be replaced by the somewhat more efficient (and dryer) electrical resistance dimmer.

See also: RESISTANCE DIMMER, AUTOTRANSFORMER DIMMER, SCR DIMMER.

MCCANDLESS, STANLEY - (c 1900 - 1967)

Stanley McCandless (American) is often regarded as the 'father' of modern stage lighting design. He worked as a teacher, educator and lighting designer, throughout his career. After graduating from the University of Wisconsin, "Mac" got his degree in architecture at Harvard. He then worked as an architect for some time and in the late 1920's he opened an office in New York City as an independent lighting consultant. He was the architectural lighting consultant for Radio City Music Hall and many other important projects. With the opening of the Yale School or Drama in the 1920's he was asked to teach stage lighting. He taught at Yale between 1925 and his retirement in 1964.

McCandless wrote two very important books on stage lighting "A method of lighting the Stage" (1st published, 1928), and "A Syllabus of Stage Lighting". McCandless provided a 'method' of l