Conclusions

L'auteur est confiant quant au fait que les lumières qu'il a vu constituaient en fait un bon aperçu de ce qu'on appelle la lumière de Brown Mountain. Il n'a pas seulement la parole de M. Loven pour soutenir cette conclusion, mais est certain que les lumières qu'il a vues s'accordent de près en apparence et en comportement avec celles décrites à l'origine dans le Charlotte Daily Observer et par le professeur Perry. Les lumières observées n'ont rien de commun avec la lumière des Andes ou avec le feu de Saint Elme. Il n'y a pas de fondement géologique à l'idée que les lumières sont des merveilles naturelles de quelque sorte que ce soit, mais il y a certaines caractéristiques de surface et conditions atmosphériques intéressantes effectives lors de la production de certaines des apparitions de la lumière.

En se référant à la carte on notera que la vallée de Catawba à l'est de Marion est une zone de type bassin ? une zone entourée de montagnes, dont la Blue Ridge au nord, avec sa frange de southward-projecting spurs, constitue la partie la plus élevée et la plus rugged. After sunset cool air begins to creep down the tributary valleys into the basin, but the air currents come from different sources and are of different temperature and density. The atmospheric conditions in the basin are therefore very unstable, especially in the earlier part of the evening, before any well-defined circulatory system becomes established. At any given place in the basin the air varies in density during the evening and hence in refractiveness. The denser the air, the more it refracts light or bends waves of light emanating from any source. The humidity of the air affects its density and hence its refractive power. Mist, dust, and other fine particles tend to obscure and scatter the light refracted and to impart to it the reddish or yellowish tints so frequently observed. Thus it is that the light is most active in a clearing spell after a rain, as noted by many observers. When the mist is very dense, the light is completely obscured.

Lights that arise from any source in the basin are viewed at low angles. Even those observed from altitudes of 3500 ou 4000 pieds, the heights of the stations on Gingercake or on Blowing Rock Mountain, had vertical angles of less than 3°. Thus, the refractive effect of the atmosphere through which the light waves must travel is at a maximum.

The effect of variations in the density of the atmosphere between the observer and the source of light is at one time to increase and at another time to diminish the intensity of the light. This fact accounts for the flares on lines 1 and 13. The diminution of a light after such a flare is so marked that to the casual observer or to one without a fieldglass the light may seem to be completely extinguished. In the telescope, however, it still appears in the same relative position, though it is somewhat fainter. Lights that are in view for brief periods, such as the headlights of automobiles or locomotives, which show only when they are turned toward the observer, produce similar flares; but when they are turned in other directions, they become extinguished so far as the observer at a given station is concerned.

Probably few if any basins on the Blue Ridge front are so favorably located as to show as well as this one the atmospheric phenomena described, and the opportunities here for the observation of such phenomena are perhaps no less exceptional. Loven's Hotel and Blowing Rock, which are resorts that attract fishermen or tourists, are among the most favorable places of observation. The valley is fairly well settled and has a network of roads, three railroads, and several large towns, so that the possible sources of light are very numerous.

As the basin and its atmospheric conditions antedate the earliest settlement of the region, it is possible that even among the first settlers some favorably situated light may have attracted attention by seeming to flare and then diminish or go out, As the country became more thickly settled the number of chances for such observations would increase. Before the advent of electric lights, however, it is doubtful whether such observations could have been sufficiently numerous to cause much comment, though some persons may have noted and remarked upon them.

According to local estimates electric lights have been in use in the larger towns of the region for about 30 years. Lights from those towns viewed from the locality near Loven's, which for a long time was the only locality from which the lights were observed, are, with the exception of those from Morganton and Blowing Rock, all seen over Brown Mountain hence the "prescribed -circle" mentioned by Colonel Harris.

L'utilisation de puissants phares électriques sur les locomotives des voies ferrées, qui commença autour de 1909, furnished new sources of strong lights in the valley and introduced an element of regularity in their appearance, which may account for the "punctual regularity" noted in the first description. After Rev. C. E. Gregory took up his summer residence near Loven's Hotel, in 1910, the Brown Mountain light began to acquire notoriety. Meanwhile, automobiles were coming into use throughout the country, and many of them were equipped with powerful headlights. Within the last few years their number has been greatly increased, and this fact is in keeping with the general deduction already made ? that on a favorable evening the lights are seen more frequently now than formerly.

Lors de l'innondation de 1916, lorsque le service de trains était temporairement interrompu, the basin east of Marion, where the atmospheric conditions are disturbed, was still the scene of the intermittent flare of favorably situated lights. Automobiles were then in use in the larger towns and on some of the intervening roads, and their headlights were doubtless visible from Loven's over Brown Mountain. One need only remember the network of roads in the valley region (see topographic maps of the Morganton and Hickory quadrangles) to realize the almost infinite number of possibilities for automobile headlights to be pointed toward Brown Mountain and stations of observation beyond. It should be emphasized, too, that automobile headlights and locomotive headlights, when seen at distances and under atmospheric conditions such as those which prevail in this region, possess no characteristic that clearly distinguishes them from other lights. On the contrary, as stated by the lady at Blowing Rock, they look "as much alike as so many peas in a pod,". though this statement should not be understood to mean that some may not be brighter than others. Col. Wade H. Harris, in his letter to Senator Simmons already cited, says: Un phare de locomotive est facilement et sans équivoque distingué comme tel, non seulement par les rayons qu'il projette, mais par ses mouvements (...). Elle [la lumière de Brown Mountain] est aussi distincte en caractéristiques d'un phare de locomotive qu'une flamme de bougie flame l'est d'un naked arc light." Encore une fois, dans un article du Charlotte Observer du 27 mars 1922, le même auteur ajoute qu'un phare a des caractéristiques qui l'identifient distinctlement et sans équivoque comme tel.

Les observations de l'auteur, faites en compagnie de personnes depuis longtemps familières avec la lumière, n'ont pu substantiate these statements. Sur les 23 lumières noted by instrumental observation and recorded on lines 1 to 21, seven proved to originate from locomotive headlights, and an eighth (n° 19) is probably of similar origin, though the data are insufficient to establish that fact, but none of these seven lights cast a beam or possessed any special quality that distinguished it from the other lights observed, and only one of them (n° 16) was known at the time of observation to be a locomotive headlight. The other six were identified as such only after the lines and angles of the record had been plotted, profiles had been drawn, and train schedules had been checked some days after the observations were made. A locomotive headlight seen at distances such as those from which the Brown Mountain light is observed has no visible motion and emits no "rays. II When its line of direction coincides with the line of observation, the light flashes on or, if the air is misty, it flares, much as an incandescent electric light flares when it is turned on. When its line of direction leaves the line of observation, the light flahses appears just as suddenly as it came. The behavior of headlights in the Brown Mountain region in this respect is comparable to that of the lights in the lighthouses on the Atlantic Coast. From the seawall at Gloucester, Mass., the writer has repeatedly seen the light at Minots Ledge, southeast of Boston, nearly 25 miles away in a direct line. This light is identified by a series of flashes that may be represented by the numerals 1-4-3. There is no beam and there are no rays. The light cannot be seen unless the air is fairly clear. Then it simply flashes once, four times, three times, and it has much the same appearance as the Brown Mountain light.

The supposed motion of the light at times may be due to errors of observation. Reference has already been made here to the fact that two observers who were present with the writer at station A thought they saw the light move when it was actually motionless as seen in the telescope. Some years ago McNeilly Du Bose, an engineer then employed near Morganton, tested observations made by himself and others by tying a cord across the fork of a tree in a place where "he could see the light across the cord and was surprised to find that the light was stationary with respect to the cord. Professor Perry. whose letter has been quoted, notes that the light was uniformly stationary when he saw it. The eye is easily deceived at night as to the stability or motion of an object, and an observer's impressions are to a considerable extent affected by his mental and physical condition at the time of observation. It is not surprising that under the circumstances different eyewitnesses give quite different accounts of the light, especially as the light may appear suddenly against a dark background with nothing nearby that can be used as a scale to determine its size or its possible motion.

Reste de la question de l'identité de la lumière de Brown Mountain telle que vue depuis Blowing Rock. M. Martin a spécifié 2 requirements: namely, the light must be seen over Brown Mountain and it must have motion. The element of motion has already been considered.

L'arc de vue intercepté par Brown Mountain est un peu plus grand que l'arc entre les lignes D et F sur la carte accompanying (fig. 1). Line D is drawn to a road that seems to be a thoroughfare near Brindletown. Line E is drawn tangent to the Southern Railway near Thermal City. Just east of this line is a thoroughfare and a short distance farther east is the track of the Carolina, Clinchfield & Ohio Railway. Line F is drawn to the same road and railroads a few miles farther northwest.

Automobile headlights on any of the numerous roads that point toward Blowing Rock within the area designated and south of Catawba River would be visible from Blowing Rock over Brown Mountain.

Il a été dit à l'auteur à Blowing Rock qu'une bonne heure pour voir la lumière était de 21 h 30 à 10 h ou un peu plus tard. L'agent de la Voie Ferrée du Sud à Thermal City indique qu'un train vers le nord sur cette voie passe cette station vers 21 h 30, maintenant approximativement le même planning tout au long de l'année. L'agent à Glenwood sur la même voie ferrée rapporte qu'un train est attendu là-bas à 21 h 53 tout au long de l'année. Les données pour les autres lignes ferroviaires ne sont pas disponibles mais il y a sans doute dessus du frêt du soir pour le nord. La concordance entre le planning du train avec la déclaration ci-dessus sur l'heure pour voir les lumières est certainement plus qu'une coïncidence.

On pourrait poser la question de savoir si un phare de locomotive pourrait être vu depuis une distance si grande que celle qui sépare Blowing Rock et Thermal City, qui est de 45 miles environ. La lumière de Minots Ledge, déjà mentionnée, est évaluée à 75 000 bougies par le Bureau des Phares et est visible à des distances supérieures à 25 miles. Il a été dit à l'auteur par M. Chadwick, du Département d'Ingéniérie de la Voie Ferrée du Sud, que les phares couramment utilisés sur ce système sont des lampes à incandescence à nitrogen rated at 250 watts and 32 volts. Fitted with 16-inch silvered-copper parabolic reflectors, these lights yield about 600 000 candlepower. Il n'y a par conséquent pas de raison de douter du fait que les phares seraient visibles à une distance de 45 miles.

The high power of these lights accounts for the brilliancy ascribed to the Brown Mountain light by observers who have seen it when the air was exceptionally clear, and it also accounts for the fact that some of the lights seen are brighter than others. En résumé on pourrait dire que les lumières de Brown Mountain ne sont clairement pas de nature ou d'origine inhabituelle. Environ 47 % des lumières que l'auteur a pu étudier instrumentalement étaient dues à des phares d'automobile, 33 % à des phares de locomotive, 10 % à des lumières stationnaires et 10 % à des feux de broussailles.