James Motley (1848), Notes to the Canwyll Corph; Note 3 in Tales of the Cymry. London: Longmans, and Hughes; Swansea: Brewster; and Llanelly: Thomas. pp.112-115.
Sean B. Palmer"'Tis but the bogfire's pale deceitful glance."
Although few, excepting the inhabitants of mountainous countries, have seen "that merry wanderer of the night," Will-o'the-Wisp, all must have read and heard many a ghastly tale of [hap]less benighted wanderers "lured to their doom" in [swampy] quagmire, by these "flying phantoms," which are generally believed by the ignorant to be evil spirits. Some years ago, the form, face, and wings of the "animal," said to be the nucleus of this light, were circumstantially described in a short paper in the Mirror, which seemed to bear the marks of implicit faith on the part of the narrator. The writer has repeatedly seen this singular light both upon bogs, and even upon the mountain roads of Glamorganshire, dancing along before him, and apparently adapting its pace to that of his horse; and so closely does it often resemble the light from a lantern carried by a person walking, that it requires a little resolution on a dark night, to avoid following it, when it leaves the road for some boggy place, as it almost always eventually does. In such cases the luminous appearance probably arises from phosphoretted hydrogen gas produced by the decomposition of some organic matter, like the light from decaying wood; but in many instances, the nocturnal wanderers seem to be of electrical origin, when the ears of the traveller's horse, the extremity of his whip, his spurs, or any other projecting points appear tipped with pencils of light. The writer was once witness to this in an very extraordinary degree, during cold weather in the month of January, 1842, on the mountain road from Maesteg to Aberafon: upon this occasion, the toes of the rider's boots, and even the tufts of hair at the fetlocks of his horse, appeared to burn with a steady blue light, and on the hand being extended, every finger immediately became tipped with fire. All these appearances are known by the Welsh by the name of Ellyl Dân or "Goblin fire." A small valley, a tributary of the Rhondda fawr on the Monmouthshire frontier of Glamorgan, is said to be very remarkable for the brilliancy and frequency of these appearances, which have gained for it the reputation of being haunted also by spirits of darker character; if the writer mistakes it not, it is a goblin of this dingle of which the Reverend Edmund Jones gives an authentic figure, in his veracious work on Welsh supersititions; these stories have earned for the dell the name of the Valley of glooms or spirits.
Mr. Allies says, that some of the strange lights of the Welsh would guide travellers into the right path, but of these I have never heard.
[Here, Motley directly quotes Allies (1840), from "In the year 1835" to "gravel interspersed thereon."]
Mr. Allies gives the following names of the Ignus fatuus [sic]: "Hoberdy's lantern", "Hobany's lantern," "Hob and his lantern," "Jack o'lantern," and "Will o'th Wisp:" to which may be added the Scotch "Spunkie."
The luminous bodies frequently seen in stormy weather upon the extemeties of the yards and trucks of the masts of vessels at sea, and known among sailors by the name of Corposants, are probably analogous to the electrical form of the Will o'th Wisp.