As the activities of man became more complex he met from his growing store of knowledge the increasing requirements of lighting. In consequence, many ingenious devices for lighting were evolved. For example, in England in the seventeenth century man was already burrowing into the earth for coal and of course encountered coal-gases. These inflammable gases were first known for the direful effects which they so often produced rather than for their useful qualities. Although they were known to miners long before they received scientific attention, the earliest account of them in the Transactions of the Royal Society was presented in the year 1667. A description of early gas-lighting has been reserved for a later chapter, but the foregoing is noted at this point to introduce a novel early method of lighting in coal-mines where inflammable gases were encountered. In discussing this coal-gas another early writer stated that "it will not take fire except by flame" and that "sparks do not affect it." One of the early solutions of the problem of artificial lighting under such conditions is summarized as follows:
Before the invention of Sir Humphrey Davy's Safety Lamp, this property of the gas gave rise to a variety of contrivances for affording the miners sufficient light to pursue their operations; and one of the most useful of these inventions was a mill for producing light by sparks elicited by the collision of flint and steel.
Such a stream of sparks may appear a very crude and unsatisfactory solution as judged by present standards, but it was at least an ingenious application of the facilities available at that time. Various other devices were resorted to in the coal-mines before the introduction of a safety lamp.
In discussing the candle it is necessary again to go back to an early period, for it slowly evolved in the course of many centuries. It is the natural descendant of the rushlight, the grease-lamp, and various primitive devices. Until the advent of the more scientific age of artificial lighting, the candle stood preëminent among early light-sources. It did not emit appreciable smoke or odor and it was conveniently portable and less fragile than the oil-lamp. Candles have been used throughout the Christian era and some authorities are inclined to attribute their origin to the Phœnicians. It is known that the Romans used them, especially the wax-candles, in religious ceremonies. The Phœnicians introduced them into Byzantium, but they disappeared under the Turkish rule and did not come into use again until the twelfth century.
The wax-candle was very much more expensive than the tallow-candle until the fifteenth century, when its relative cost was somewhat reduced, bringing it within the means of a greater proportion of the people. Nevertheless it has long been used, chiefly by the wealthy; the departing guest of the early Victorian inn would be likely to find an item on his bill such as this: "For a gentleman who called himself a gentleman, wax-lights, 5/." Poor men used tallow dips or went to bed in the dark. It is interesting to note the importance of the candle in the household budget of early times in various sayings. For example, "The game is not worth the candle," implies that the cost of candle-light was not ignored. In these days little attention is given to the cost of artificial light under similar conditions. If a person "burns a candle at both ends" he is wasteful and oblivious to the consequences of extravagance whether in material goods or in human energy.
With the rise of the Christian church, candles came to be used in religious ceremonies and many of the symbolisms, meanings, and customs survive to the present time. Some of the finest art of past centuries is found in the old candlesticks. Many of these antiques, which ofttimes were gifts to the church, have been preserved to posterity by the church. The influence of these lighting accessories is often noted in modern lighting-fixtures, but unfortunately early art often suffers from adaptation to the requirements of modern light-sources, or the eyesight suffers from a senseless devotion to art which results in the use of modern light-sources, unshaded and glaring, in places where it was unnecessary to shade the feeble candle.
The oldest materials employed for making candles are beeswax and tallow. The beeswax was bleached before use. The tallow was melted and strained and then cotton or flax fibers were dipped into it repeatedly, until the desired thickness was obtained. In early centuries the pith of rushes was used for wicks. Tallow is now used only as a source of stearine. Spermaceti, a fatty substance obtained from the sperm-whale, was introduced into candle-making in about 1750 and great numbers of men searched the sea to fill the growing demands. Paraffin wax, a mixture of solid hydrocarbons obtained from petroleum, came into use in 1854 and stearine is now used with it. The latter increases the rigidity and decreases the brittleness of the candle. Some of the modern candles are made of a mixture of stearine and the hard fat extracted from cocoanut-oil. Modern candles vary in composition, but all are the product of much experience and of the application of scientific knowledge. The wicks are now made chiefly of cotton yarn, braided or plaited by machinery and chemically treated to aid in complete combustion when the candle is burned. Their structure is the result of long experience and they are now made so that they bend and dip into the molten fuel and are wholly consumed. This eliminates the necessity of trimming.
Candles have been made in various ways, including dipping, pouring, drawing, and molding. Wax-candles are made by pouring, because wax cannot be molded satisfactorily. Drawing is somewhat similar to dipping, except that the process is more or less continuous and is carried out by machinery. Molding, as the term implies, involves the use of molds, of the size and shape desired.
The candlestick evolved from the most primitive wooden objects to elaborately designed and decorated works of art. The primitive candlestick was crude and was no more than a holder of some kind for keeping the candle upright. Later a form of cup was attached to the stem of the holder, to catch the dripping wax or fat. The latter improvement has persisted throughout the centuries. The modern candle is by no means an unsatisfactory light-source. Those who have had experience with it in the outskirts of civilization will testify that it possesses several desirable characteristics. Supplies of candles are transported without difficulty; the lighted candle is easily carried about; and the light in a quiescent atmosphere is quite satisfactory, if common sense is used in shading and placing the candle. Although in a sense a primitive light-source, it is a blessing in many cases and, incidentally, it is extensively used to-day in industries, in religious ceremonies, as a decorative element at banquets, and in the outposts of civilization.
This account of the evolution of light-sources has crossed the threshold of what may be termed modern scientific light-production in the case of the candle and the oil-lamp. There is a period of a century or more during which scientific progress was slow, but those years paved the way for the extraordinary developments of the last few decades.