Part 7

Fire and light have been closely associated in various religious creeds and their ceremonies. The Hindu festival in honor of the goddess of prosperity is attended by the burning of many lamps in the temples and homes. The Jewish synagogues have their eternal lamps and in their rituals fire and light have played prominent roles. The devout Brahman maintains a fire on the hearth and worships it as omniscient and divine. He expects a brand from this to be used to light his funeral pyre, whose fire and light will make his spirit fit to enter his heavenly abode. He keeps a fire burning on the altar, worships Agni, the god of fire, and makes fire sacrifices on various occasions such as betrothals and marriages. To the Mohammedans lighted lamps symbolize holy places, and the Kaaba at Mecca, which contains a black stone supposed to have been brought from heaven, is illuminated by thousands of lamps. Many of the uses to which light was put in ancient times indicate its rarity and sacred nature. Doubtless, the increasing use of artificial light at festivals and celebrations of the present time is partly the result of lingering customs of bygone centuries and partly due to a recognition of an innate appeal or attribute of light. Certainly nothing is more generally appropriate in representing joy and prosperity.

Throughout all countries ancient races had woven natural light and fire into their rites and customs, so it became a natural step to utilize artificial light and fire in the same manner. It would be tedious and monotonous to survey the vast field of ancient worship of light, for the underlying ideas are generally similar. The mythology of the Greeks is illustrative of the importance attached to fire and light by the cultivated peoples of ancient times. The myth of Prometheus emphasizes the fact that in those remote periods fire and light were regarded as of prime importance. According to this myth, fire and light were contained in heaven and great cunning and daring were necessary in order to obtain it. Prometheus stole this heavenly fire, for which act he was chained to the mountain and made to suffer. The Greeks mark this event as the beginning of human civilization. All arts are traced to Prometheus, and all earthly woe likewise. As past history is surveyed it appears natural to think of scientific men who have become martyrs to the quest of hidden secrets. They have made great sacrifices for the future benefit of civilization and not a few of them have endured persecution even in recent times. The Greeks recognized that a new era began with the acquisition of artificial light. Its divine nature was recognized and it became a phenomenon for worship and a means for representing divine presence. The origin of fire and light made them holy. The fire on the altar took its place in religious rites and there evolved many ceremonial uses of lamps, candles, and fire.

The Greeks and Romans burned sacred lamps in the temples and utilized light and fire in many ceremonies. The torch-race, in which young men ran with lighted torches, the winner being the one who reached the goal first with his torch still alight, originated in a Grecian ceremony of lighting the sacred fire. There are many references in ancient Roman and Grecian literature to sacred lamps burning day and night in sanctuaries and before statues of gods and heroes. On birthdays and festivals the houses of the Romans were specially ornamented with burning lamps. The Vestal Virgins in Rome maintained the sacred fire which had been brought by fugitives from Troy. In ancient Rome when the fire in the Temple of Vesta became extinguished, it was rekindled by the rubbing of a piece of wood upon another until fire was obtained. This was carried into the temple by the Vestal Virgin and the sacred fire was rekindled. The fire produced in this manner, for some reason, was considered holy.

The early peoples displayed many lamps on feast-days and an example of extravagance in this respect is an occasion when King Constantine commanded that the entire city of Constantinople be illuminated by wax-candles on Christmas Eve. Candelabra, of the form of the branching tree, were commonly in use in the Roman temples.

The ceremonial use of light in the Christian church evolved both from adaptations of pagan customs and of the natural symbolisms of fire and light. However, these acquired a deeper meaning in Christianity than in early times because they were primarily visible representations or manifestations of the divine presence. The Bible contains many references to the importance and symbolisms of light and fire. According to the First Book of Moses, the achievement of the Creator immediately following the creation of "the heavens and the earth" was the creation of light. The word "light" is the forty-sixth word in Genesis. Christ is "the true light" and Christians are "children of light" in war against the evil "powers of darkness." When St. Paul was converted "there shined about him a great light from heaven." The impressiveness and symbolism of fire and light are testified to in many biblical expressions. Christ stands "in the midst of seven candle-sticks" with "his eyes as a flame of fire." When the Holy Ghost appeared before the apostles "there appeared unto them cloven tongues of fire." When St. Paul was preaching the gospel of Christ at Alexandria "there were many lights" suggesting a festive illumination.

According to the Bible, the perpetual fire which came originally from heaven was to be kept burning on the altar. It was holy and those whose duty it was to keep it burning were guilty of a grave offense if they allowed it to be extinguished. If human hands were permitted to kindle it, punishment was meted out. The two sons of Aaron who "offered strange fire before the Lord" were devoured by "fire from the Lord." The seven-branched candlestick was lighted eternally and these burning light-sources were necessary accompaniments of worship.

The countless ceremonial uses of fire and light which had evolved in the past centuries were bound to influence the rites and customs of the Christian church. The festive illumination of pagan temples in honor of gods was carried over into the Christian era. The Christmas tree of to-day is incomplete without its many lights. Its illumination is a homage of light to the source of light. The celebration of Easter in the Church of the Holy Sepulchre in Jerusalem is a typical example of fire-worship retained from ancient times. At the climax of the services comes the descent of the Holy Fire. The central candelabra suddenly becomes ablaze and the worshipers, each of whom carries a wax taper, light their candles therefrom and rush through the streets. The fire is considered to be of divine origin and is a symbol of resurrection. The custom is similar in meaning to the light which in older times was maintained before gods.

During the first two or three centuries of the Christian era the ceremonial use of light does not appear to have been very extensive. Writings of the period contain statements which appear to ridicule this use to some extent. For example, one writer of the second century states that "On days of rejoicing ... we do not encroach upon daylight with lamps." Another, in the fourth century, refers with sarcasm to the "heathen practice" in this manner: "They kindle lights as though to one who is in darkness. Can he be thought sane who offers the light of lamps and candles to the Author and Giver of all light?"

That candles were lighted in cemeteries is evidenced by an edict which forbade their use during the day. Lamps of the early centuries of the Christian era have been found in the catacombs of Rome which are thought to have been ceremonial lamps, for they were not buried with the dead. They were found only in niches in the walls. During these same centuries elaborate candelabra containing hundreds of candles were kept burning before the tombs of saints. Notwithstanding the doubt that exists as to the extent of ceremonial lighting in the early centuries of the Christian era, it is certain that by the beginning of the fifth century the ceremonial use of light in the Christian church had become very extensive and firmly established. That this is true and that there were still some objections is indicated by many controversies. Some thought that lamps before tombs were ensigns of idolatry and others felt that no harm was done if religious people thus tried to honor martyrs and saints. Some early writings convey the idea that the ritualistic use of lights in the church arose from the retention of lights necessary at nocturnal services after the hours of worship had been changed to daytime.

Passing beyond the early controversial period, the ceremonial use of light is everywhere in evidence at ordinary church services. On special occasions such as funerals, baptisms, and marriages, elaborate altar-lighting was customary. The gorgeous candelabra and the eternal lamp are noted in many writings. Early in the fifth century the pope ordered that candles be blessed and provided rituals for this ceremony. Shortly after this the Feast of Purification of the Virgin was inaugurated and it became known as Candlemas because on this day the candles for the entire year were blessed. However, it appears that the blessing of candles was not carried out in all churches. Altar lights were not generally used until the thirteenth century. They were originally the seven candles carried by church officials and placed near the altar.

The custom of placing lighted lamps before the tombs of martyrs was gradually extended to the placing of such lamps before various objects of a sacred or divine relation. Finally certain light-sources themselves became objects of worship and were surrounded by other lamps, and the symbolisms of light grew apace. A bishop in the sixth century heralded the triple offering to God represented by the burning wax-candle. He pointed out that the rush-wick developed from pure water; that the wax was the product of virgin bees; and that the flame was sent from heaven. Each of these, he was certain, was an offering acceptable to God. Wax-candles became associated chiefly with religious ceremonies. The wax later became symbolic of the Blessed Virgin and of the body of Christ. The wick was symbolical of Christ's soul, the flame represented his divine character, and the burning candle thus became symbolical of his death. The lamp, lantern, and taper are frequently symbols of piety, heavenly wisdom, or spiritual light. Fire and flames are emblems of zeal and fervor or of the sufferings of martyrdom and the flaming heart symbolizes fervent piety and spiritual or divine love.

By the time the Middle Ages were reached the ceremonial uses of light became very complex, but for the Roman Catholic Church they may be divided into three general groups: (1) They were symbolical of God's presence or of the effect of his presence; of Christ or of "the children of light"; or of joy and content at festivals. (2) They may be offered in fulfillment of a religious vow; that is, as an act of worship. (3) They may possess certain divine power because of their being blessed by the church, and therefore may be helpful to soul and body. The three conceptions are indicated in the prayers offered at the blessing of the candles on Candlemas as follows: (1) "O holy Lord ... who ... by thy command didst cause this liquid to come by the labor of bees to the perfection of wax, ... we beseech thee ... to bless and sanctify these candles for the use of men, and the health of bodies and souls...." (2) "...these candles, which we thy servants desire to carry lighted to magnify thy name; that by offering them to thee, being worthily inflamed with the holy fire of thy most sweet charity, we may deserve...." (3) "O Lord Jesus Christ, the true light, ... mercifully grant, that as these lights enkindled with visible fire dispel nocturnal darkness, so our hearts illuminated by visible fire," etc.

In general, the ceremonial uses of lights in this church were originated as a forceful representation of Christ and of salvation. On the eve of Easter a new fire, emblematic of the arisen Christ, is kindled, and all candles throughout the year are lighted from this. During the service of Holy Week thirteen lighted candles are placed before the altar and as the penitential songs are sung they are extinguished one by one. When but one remains burning it is carried behind the altar, thus symbolizing the last days of Christ on earth. It is said that this ceremony has been traced to the eighth century. On Easter Eve, after the new fire is lighted and blessed, certain ceremonies of light symbolize the resurrection of Christ. From this new fire three candles are lighted and from these the Paschal Candle. The origin of the latter is uncertain, but it symbolizes a victorious Christ. From it all the ceremonial lights of the church are lighted and they thereby are emblematic of the presence of the light of Christ.

Many interesting ceremonial uses may be traced out, but space permits a glimpse of only a few. At baptismal services the paschal candle is dipped into the water so that the latter will be effective as a regenerative element. The baptized child is reborn as a child of light. Lighted candles are placed in the hands of the baptized persons or of their god-parents. Those about to take vows carry lights before the church official and the same idea is attached to the custom of carrying or of holding lights on other occasions such as weddings and first communion. Lights are placed around the bodies of the dead and are carried at the funeral. They not only protect the dead from the powers of darkness but they symbolize the dead as still living in the light of Christ. The use of lighted candles around bodies of the dead still survives to some extent among Protestants, but their significance has been lost sight of. Even in the eighteenth century funerals in England were accompanied by lighted tapers, but the carrying of lights in other processions appears to have ceased with the Reformation. In some parts of Scotland it is still the custom to place two lighted candles on a table beside a corpse on the day of the funeral.

With the importance of light in the ritual of the church it is not surprising that the extinction of lights is a part of the ceremony of excommunication. Such a ceremony is described in an early writing thus: "Twelve priests should stand about the bishop, holding in their hands lighted torches, which at the conclusion of the anathema or excommunication they should cast down and trample under foot." When the excommunicant is reinstated, a lighted candle is placed in his hands as a symbol of reconciliation. These and many other ceremonial uses of light have been and are practised, but they are not always mandatory. Furthermore, the customs have varied from time to time, but the few which have been touched upon illustrate the impressive part that light has played in religious services.

During the Reformation the ceremonial use of lights was greatly altered and was abolished in the Protestant churches as a relic of superstition and papal authority. In the Lutheran churches ceremonial lights were largely retained, in the Church of England they have been subjected to many changes largely through the edicts of the rulers. In the latter church many controversies were waged over ceremonial lights and their use has been among the indictments of a number of officials of the church in impeachment cases before the House of Commons. Many uses of light in religious ceremonies were revived in cathedrals after the Restoration and they became wide-spread in England in the nineteenth century. As late as 1889 the Archbishop of Canterbury ruled that certain ceremonial candles were lawful according to the Prayer-Book of Edward VI, but the whole question was left open and unsettled.

These byways of artificial light are complex and fascinating because their study leads into many channels and far into the obscurity of the childhood of the human race. A glimpse of them is important in a survey of the influence of artificial light upon the progress of civilization because in these usages the innate and acquired impressiveness of light is encountered. Although many ceremonial uses of light remain, it is doubtful if their significance and especially their origin are appreciated by most persons. Nevertheless, no more interesting phase of artificial light is encountered than this, which reaches to the foundation of civilization.

OIL-LAMPS OF THE NINETEENTH CENTURY

It will be noted that the light-sources throughout the early ages were flames, the result of burning material. This principle of light-production has persisted until the present time, but in the latter part of the nineteenth century certain departures revolutionized artificial lighting. However, it is not the intention to enter the modern period in this chapter except in following the progress of the oil-lamp through its period of scientific development. The oil-lamp and the candle were the mainstays of artificial lighting throughout many centuries. The fats and waxes which these light-sources burned were many but in the later centuries they were chiefly tallow, sperm-oil, spermaceti, lard-oil, olive-oil, colza-oil, bees-wax and vegetable waxes. Those fuels which are not liquid are melted to liquid form by the heat of the flame before they are actually consumed. The candle is of the latter type and despite its present lowly place and its primitive character, it is really an ingenious device. Its fuel remains conveniently solid so that it is readily shipped and stored; there is nothing to spill or to break beyond easy repair; but when it is lighted the heat of its flame melts the solid fuel and thus it becomes an "oil-lamp." Animal and vegetable oils were mainly used until the middle of the nineteenth century, when petroleum was produced in sufficient quantities to introduce mineral oils. This marked the beginning of an era of developments in oil-lamps, but these were generally the natural offspring of early developments by Ami Argand.

Before man discovered that nature had stored a tremendous supply of mineral oil in the earth he was obliged to hunt broadcast for fats and waxes to supply him with artificial light. He also was obliged to endure unpleasant odors from the crude fuels and in early experiments with fats and waxes the odor was carefully noted as an important factor. Tallow was a by-product of the kitchen or of the butcher. Stearine, a constituent of tallow, is a compound of glyceryl and stearic acid. It is obtained by breaking up chemically the glycerides of animal fats and separating the fatty acids from glycerin. Fats are glycerides; that is, combinations of oleic, palmetic, and stearic acids. Inasmuch as the former is liquid at ordinary temperatures and the others are solid, it follows that the consistency or solidity of fats depend upon the relative proportions of the three constituents. The sperm-whale, which lives in the warmer parts of all the oceans, has been hunted relentlessly for fuels for artificial lighting. In its head cavities sperm-oil in liquid form is found with the white waxy substance known as spermaceti. Colza-oil is yielded by rape-seed and olive-oil is extracted from ripe olives. The waxes are combinations of allied acids with bases somewhat related to glycerin but of complex composition. Fats and waxes are more or less related, but to distinguish them carefully would lead far afield into the complexities of organic chemistry. All these animal and vegetable products which were used as fuels for light-sources are rich in carbon, which accounts for the light-value of their flames. The brightness of such a flame is due to incandescent carbon particles, but this phase of light-production is discussed in another chapter. These oils, fats, and waxes are composed by weight of about 75 to 80 per cent. carbon; 10 to 15 per cent. hydrogen; and 5 to 10 per cent. oxygen.

Until the middle of the eighteenth century the oil-lamps were shallow vessels filled with animal or vegetable oil and from these reservoirs short wicks projected. The flame was feeble and smoky and the odors were sometimes very repugnant. Viewing such light-sources from the present age in which light is plentiful, convenient, and free from the great disadvantages of these early oil-lamps, it is difficult to imagine the possibility of the present civilization emerging from that period without being accompanied by progress in light-production. The improvements made in the eighteenth century paved the way for greater progress in the following century. This is the case throughout the ages, but there are special reasons for the tremendous impetus which light-production has experienced in the past half-century. These are the acquirement of scientific knowledge from systematic research and the application of this knowledge by organized development.

The first and most notable improvement in the oil-lamp was made by Argand in 1784. Our nation was just organizing after its successful struggle for independence at the time when the production of light as a science was born. Argand produced the tubular wick and contributed the greatest improvement by being the first to perform the apparently simple act of placing a glass chimney upon the lamp. His burner consisted of two concentric metal tubes between which the wick was located. The inner tube was open, so that air could reach the inner surface of the wick as well as the outer surface. The lamp chimney not only protected the flame from drafts but also improved combustion by increasing the supply of air. It rested upon a perforated flange below the burner. If the glass chimney of a modern kerosene lamp be lifted, it will be noted that the flame flickers and smokes and that it becomes steady and smokeless when the chimney is replaced. The advantages of such a chimney are obvious now, but Argand for his achievements is entitled to a place among the great men who have borne the torch of civilization. He took the first step toward adequate artificial light and opened a new era in lighting.

The various improvements of the oil-lamp achieved by Argand combined to effect complete combustion, with the result that a steady, smokeless lamp of considerable luminous intensity was for the first time available. Many developments followed, among which was a combination of reservoir and gravity feed which maintained the oil at a constant level. In later lamps, upon the adoption of mineral oil, this was found unnecessary, perhaps owing to the construction of the wick and to the physical characteristics of the oil which favored capillary action in the wick. However, the height of the oil in the reservoir of modern oil-lamps makes some difference in the amount of light emitted.

The Carcel lamp, which appeared in 1800, consisted of a double piston operated by clockwork. This forced the oil through a tube to the burner. Franchot invented the moderator lamp in 1836, which, because of its simplicity and efficiency soon superseded many other lamps designed for burning animal and vegetable oils. The chief feature of the moderator lamp is a spiral spring which forces the oil upward through a vertical tube to the burner. These are still used to some extent in France, but owing to the fact that "mechanical" lamps eventually were very generally replaced by more simple ones, it does not appear necessary to describe these complex mechanisms in detail.

When coal is distilled at moderate temperatures, volatile liquids are obtained. These hydrocarbons, being inflammable, naturally attracted attention when first known, and in 1781 their use as fuel for lamps was suggested. However, it was not until 1820 that the light oils obtained by distilling coal-tar, a by-product of the coal-gas industry which was then in its early stage of development, were burned to some extent in the Holliday lamp. In this lamp the oil is contained in a reservoir from the bottom of which a fine metal tube carries the oil down to a rose-burner. The oil is heated by the flame and the vaporized mineral oil which escapes through small orifices is burned. This type of lamp has undergone many physical changes, but its principle survives to the present time in the gasolene and kerosene burners hanging on a pole by the side of the street-peddler's stand.

Although petroleum products were not used to any appreciable extent for illuminating-purposes until after the middle of the nineteenth century, mineral oil is mentioned by Herodotus and other early writers. In 1847 petroleum was discovered in a coal-mine in England, but the supply failed in a short time. However, the discoverer, James Young, had found that this oil was valuable as a lubricant and upon the failure of this source he began experiments in distilling oil from shale found in coal deposits. These were destined to form the corner-stone of the oil industry in Scotland. In 1850 he began producing petroleum in this manner, but it was not seriously considered for illuminating-purposes. However, in Germany about this time lamps were developed for burning the lighter distillates and these were introduced into several countries. But the price of these lighter oils was so great that little progress was made until, in 1859, Col. E. L. Drake discovered oil in Pennsylvania. By studying the geological formations and concluding that oil should be obtained by boring, Drake gave to the world a means of obtaining petroleum, and in quantities which were destined to reduce the price of mineral oil to a level undreamed of theretofore. To his imagination, which saw vast reservoirs of oil in the depths of the earth, the world owes a great debt. Lamps were imported from Germany to all parts of the civilized world and the kerosene lamp became the prevailing light-source. Hundreds of American patents were allowed for oil-lamps and their improvements in the next decade.

The crude petroleum, of course, is not fit for illuminating purposes, but it contains components which are satisfactory. The various components are sorted out by fractional distillation and the oil for burning in lamps is selected according to its volatility, viscosity, stability, etc. It must not be so volatile as to have a dangerously low flashing-point, nor so stable as to hinder its burning well. In this fractional distillation a vast variety of products are now obtained. Gasolene is among the lighter products, with a density of about 0.65; kerosene has a density of about 0.80; the lubricating-oils from 0.85 to 0.95; and there are many solids such as vaseline and paraffin which are widely used for many purposes. This process of refining oils is now the source of paraffin for making candles, in which it is usually mixed with substances like stearin in order to raise its melting-point.

Crude petroleum possesses a very repugnant odor; it varies in color from yellow to black; and its specific gravity ranges from about 0.80 to 1.00, but commonly is between 0.80 and 0.90. Its chemical constitution is chiefly of carbon and hydrogen, in the approximate ratio of about six to one respectively. It is a mixture of paraffin hydrocarbons having the general formula of C{n}H{2n+2} and the individual members of this series vary from CH{4} (methane) to C{15}H_{32} (pentadecane), although the solid hydrocarbons are still more complex. Petroleum is found in many countries and the United States is particularly blessed with great stores of it.