Earth Connexion.—A copper plate not less than 3 sq. ft. in area may be used as an earth connexion if buried in permanently damp ground. Instead of a plate there are advantages in using the tubular earth shown in fig. 5. The cable packed in carbon descends to the bottom of the perforated tube which is driven into the ground, a connexion being made to the nearest rain-water pipe to secure the necessary moisture. No further attention is required. Plate earths should be tested every year. The number of earths depends on the area of the building, but at least two should be provided. Insulators on the conductor are of no advantage, and it is useless to gild or otherwise protect the points of the air-terminals. As heated air offers a good path for lightning (which is the reason why the kitchen-chimney is often selected by the discharge), a number of points should be fixed to high chimneys and there should be at least two conductors to earth. All roof metals, such as finials, flashings, rain-water gutters, ventilating pipes, cowls and stove pipes, should be connected to the system of conductors. The efficiency of the installation depends on the interconnexion of all metallic parts, also on the quality of the earth connexions. In the case of magazines used for explosives, it is questionable whether the usual plan of erecting rods at the sides of the buildings is efficient. The only way to ensure safety is to enclose the magazine in iron; the next best is to arrange the conductors so that they surround it like a bird cage.
Bibliography.—The literature, although extensive, contains so many descriptions of ludicrous devices, that the student, after reading Benjamin Franklin’s Experiments and Observations on Electricity made at Philadelphia (1769), may turn to the Report of the Lightning Rod Conference of December 1881. In the latter work there are abstracts of many valuable papers, especially the reports made to the French Academy, among others by Coulomb, Laplace, Gay-Lussac, Fresnel, Regnault, &c. In 1876 J. Clerk Maxwell read a paper before the British Association in which he brought forward the idea (based on Faraday’s experiments) of protecting a building from the effects of lightning by surrounding it with a sort of cage of rods or stout wire. It was not, however, until the Bath meeting of the British Association in 1888 that the subject was fully discussed by the physical and engineering sections. Sir Oliver Lodge showed the futility of single conductors, and advised the interconnexion of all the metal work on a building to a number of conductors buried in the earth. The action of lightning flashes was also demonstrated by him in lectures delivered before the Society of Arts (1888). The Clerk Maxwell system was adopted to a large extent in Germany, and in July 1901 a sub-committee of the Berlin Electro-technical Association was formed, which published rules. In 1900 a paper entitled “The Protection of Public Buildings from Lightning,” by Killingworth Hedges, led to the formation, by the Royal Institute of British Architects and the Surveyors’ Institution, of the Lightning Research Committee, on which the Royal Society and the Meteorological Society were represented. The Report, edited by Sir Oliver Lodge, Sir John Gavey and Killingworth Hedges (Hon. Sec.), was published in April 1905. An illustrated supplement, compiled by K. Hedges and entitled Modern Lightning Conductors (1905), contains particulars of the independent reports of the German committee, the Dutch Academy of Science, and the Royal Joseph university, Budapest. A description is also given of the author’s modified Clerk Maxwell system, in which the metal work of the roofs of a building form the upper part, the rain-water pipes taking the place of the usual lightning-rods. See also Sir Oliver Lodge, Lightning Conductors (London, 1902).
(K. H.)
LIGHTS, CEREMONIAL USE OF. The ceremonial use of lights in the Christian Church, with which this article is mainly concerned, probably has a double origin: in a very natural symbolism, and in the adaptation of certain pagan and Jewish rites and customs of which the symbolic meaning was Christianized. Light is everywhere Non-Christian religions. the symbol of joy and of life-giving power, as darkness is of death and destruction. Fire, the most mysterious and impressive of the elements, the giver of light and of all the good things of life, is a thing sacred and adorable in primitive religions, and fire-worship still has its place in two at least of the great religions of the world. The Parsis adore fire as the visible expression of Ahura-Mazda, the eternal principle of light and righteousness; the Brahmans worship it as divine and omniscient.[1] The Hindu festival of Dewāli (Diyawālī, from diya, light), when temples and houses are illuminated with countless lamps, is held every November to celebrate Lakhshmi, the goddess of prosperity. In the ritual of the Jewish temple fire and light played a conspicuous part. In the Holy of Holies was a “cloud of light” (shekinah), symbolical of the presence of Yahweh, and before it stood the candlestick with six branches, on each of which and on the central stem was a lamp eternally burning; while in the forecourt was an altar on which the sacred fire was never allowed to go out. Similarly the Jewish synagogues have each their eternal lamp; while in the religion of Islam lighted lamps mark things and places specially holy; thus the Ka’ba at Mecca is illuminated by thousands of lamps hanging from the gold and silver rods that connect the columns of the surrounding colonnade.
The Greeks and Romans, too, had their sacred fire and their ceremonial lights. In Greece the Lampadedromia or Lampadephoria (torch-race) had its origin in ceremonies connected with the relighting of the sacred fire. Pausanias Greece and Rome. (i. 26, § 6) mentions the golden lamp made by Callimachus which burned night and day in the sanctuary of Athena Polias on the Acropolis, and (vii. 22, §§ 2 and 3) tells of a statue of Hermes Agoraios, in the market-place of Pharae in Achaea, before which lamps were lighted. Among the Romans lighted candles and lamps formed part of the cult of the domestic tutelary deities; on all festivals doors were garlanded and lamps lighted (Juvenal, Sat. xii. 92; Tertullian, Apol. xxxv.). In the cult of Isis lamps were lighted by day. In the ordinary temples were candelabra, e.g. that in the temple of Apollo Palatinus at Rome, originally taken by Alexander from Thebes, which was in the form of a tree from the branches of which lights hung like fruit. In comparing pagan with Christian usage it is important to remember that the lamps in the pagan temples were not symbolical, but votive offerings to the gods. Torches and lamps were also carried in religious processions.
The pagan custom of burying lamps with the dead conveyed no such symbolical meaning as was implied in the late Christian custom of placing lights on and about the tombs of Funeral lamps. martyrs and saints. Its object was to provide the dead with the means of obtaining light in the next world, a wholly material conception; and the lamps were for the most part unlighted. It was of Asiatic origin, traces of it having been observed in Phoenicia and in the Punic colonies, but not in Egypt or Greece. In Europe it was confined to the countries under the domination of Rome.[2]
In Christianity, from the very first, fire and light are conceived as symbols, if not as visible manifestations, of the divine nature and the divine presence. Christ is “the true Light” (John i. 9), and at his transfiguration “the fashion Christian symbolism of light. of his countenance was altered, and his raiment was white and glistering” (Luke ix. 29); when the Holy Ghost descended upon the apostles, “there appeared unto them cloven tongues of fire, and it sat upon each of them” (Acts ii. 3); at the conversion of St Paul “there shined round him a great light from heaven” (Acts ix. 3); while the glorified Christ is represented as standing “in the midst of seven candlesticks ... his head and hairs white like wool, as white as snow; and his eyes as a flame of fire” (Rev. i. 14, 15). Christians are “children of Light” at perpetual war with “the powers of darkness.”
All this might very early, without the incentive of Jewish and pagan example, have affected the symbolic ritual of the primitive Church. There is, however, no evidence of The early Church. any ceremonial use of lights in Christian worship during the first two centuries. It is recorded, indeed (Acts xx. 7, 8), that on the occasion of St Paul’s preaching at Alexandria in Troas “there were many lights in the upper chamber”; but this was at night, and the most that can be hazarded is that a specially large number were lighted as a festive illumination, as in modern Church festivals (Martigny, Dict. des antiqu. Chrét.). As to a purely ceremonial use, such early evidence as exists is all the other way. A single sentence of Tertullian (Apol. xxxv.) sufficiently illuminates Christian practice during the 2nd century. “On days of rejoicing,” he says, Tertullian and Lactantius. “we do not shade our door-posts with laurels nor encroach upon the day-light with lamps” (die laeto non laureis postes obumbramus nec lucernis diem infringimus). Lactantius, writing early in the 4th century, is even more sarcastic in his references to the heathen practice. “They kindle lights,” he says, “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?” (Div. Inst. vi. de vero cultu, cap. 2, in Migne, Patr. lat. vi. 637).[3] This is primarily an attack on votive lights, and does not necessarily exclude their ceremonial use in other ways. There is, indeed, evidence that they were so used before Lactantius wrote. The 34th canon of the synod of Elvira (305), which was contemporary with him, forbade candles to be lighted in cemeteries during the day-time, which points to an established custom as well as to an objection to it; and in the Roman catacombs lamps have been found of the 2nd and 3rd centuries which seem to have been ceremonial or symbolical.[4] Again, according to the Acta 2nd and 3rd centuries. of St Cyprian (d. 258), his body was borne to the grave praelucentibus cereis, and Prudentius, in his hymn on the martyrdom of St Lawrence (Peristeph. ii. 71, in Migne, Patr. lat. lx. 300), says that in the time of St Laurentius, i.e. the middle of the 3rd century, candles stood in the churches of Rome on golden candelabra. The gift, mentioned by Anastasius (in Sylv.), made by Constantine to the Vatican basilica, of a pharum of gold, garnished with 500 dolphins each holding a lamp, to burn before St Peter’s tomb, points also to a custom well established before Christianity became the state religion.
Whatever previous custom may have been—and for the earliest ages it is difficult to determine absolutely owing to the fact Jerome and Vigilantius. that the Christians held their services at night—by the close of the 4th century the ceremonial use of lights had become firmly and universally established in the Church. This is clear, to pass by much other evidence, from the controversy of St Jerome with Vigilantius.