My God is
the green tide in the spring leaves
the redness of cherries high in the air
the excitement of shooting stars
the song of birds in summer branches
the sunrise on a winter’s morning
the name of everything we don’t understand
– William of Ockham

Do you smell swamp gas?

I like a good old fashioned UFO sighting.  Never seen one myself, but I do have a few mysterious gaps in my memory, although these are better attributed to my fondness for certain beverages than any sort of alien abduction scenario.  And while Ancient Aliens is endlessly amusing, engaging in that sort of historical reinterpretation is problematic for a number of reasons from unabashed historical presentism to the condescending notion that humans aren’t capable of impressive feats, thus must have been extraterrestrially influenced, to a breathless need to contradict any mainstream interpretation, no matter how thin the contradictory evidence or unnecessary to an actual explanation.  Nonetheless, I understand the temptation, as every once in a while I run across a little historical snippet that screams to be interpreted as a visit from some ne’er-do-well critter that’s not of this world.  Case in point, the Harlech Meteor of 1694 in Wales, which is oddly named as we know it was pretty much anything but an actual meteor.  We like to assume a 17th Century Welshman would be unerringly superstitious when it comes to lights in the sky, but who wouldn’t reach for some sort of explanation when strange lights routinely appeared, set your hay on fire, killed your lawn, and slaughtered your livestock.  And explanations were forthcoming from those who simply knew that there is nothing preternatural in the universe.  Smug bastards.

Between Harlech and the Caernarvonshire side of the Traeth By-chan intervenes a low range of marsh land, running up some way into the country. Just before Christmas, 1693, a pale blue light was observed to come across the sea, apparently from the Caernarvonshire coast, and moving slowly from one part of the neighbouring country to another, to fire all the hay-ricks and some of the barns which it approached. It never appeared but at night. At first the country people were terrified at it; at length, taking courage, they ventured boldly close to it, and sometimes into it, to save, if it might be, their hay. As summer came on, instead of appearing almost every night, its visits were confined to once or twice a week, and almost always on Saturday or Sunday. It now began to cease from firing bricks, but was hurtful in another manner; for it poisoned all the grass on which it rested, and a great mortality of cattle and sheep ensued. At length it was traced to a place called Morvabychan, in Caernarvonshire, a sandy and marshy bay, about nine miles distant from Harlech. Storm or fine weather seemed to make no difference to this meteor (Neale, 1847, p43-44).

A curious letter to the Royal Society of London in August 1694, assures a certain Dr. Lister that the Harlech depredations continue, and includes prophylactic strategies for combatting this aerial arsonist.

Letter from Mr. Edward Lhwyd, to Dr. Lister; giving some farther Account of the Fiery Exhalation in Merionethshire. Dated Oxford Aug. 23, 1694 – An intelligent person, who lives near Harlech in Merionethshire, assured me the fire still continues there; that it is observed to come from a place called Morva-bychan in Caernarvonshire, about 8 or 9 miles off, over part of the sea. That cattle of all sorts, as sheep, goats, hogs, cows and horses, still die apace; and that for certain, any great noise, as winding of horns, drums, etc. repels it from any house, or barn, or stacks of hay: on account of which remedy, they have had few or no losses in that kind since Christmas. That it happened during this summer, at least one night in a week, and that commonly either Saturday or Sunday; but that now of late it appears something oftner. The place whence it proceeds is both sandy and marshy (Lister, 1694, p672-673).

By the close of the 18th century, while learned men recognized that something bizarre had occurred in the little Welsh town of Harlech, they began to offer explanations that would have made Project Blue Book proud – Swamp Gas and Locusts.

In the winter of 1694, this neighborhood was remarkable for an amazing and noxious phenomenon. A mephites, or pestilential vapour, resembling a weak blue flame, arose, during a fortnight or three weeks, out of a sandy marshy tract, called Morfa Bychan, and crossed over a channel of eight miles to Harlech. It set fire on that side to sixteen ricks of hay and two barns, one filled with hay, the other with corn. It infected the grass in such a manner, that numbers of cattle, horses, sheep, and goats, died; yet men went into the midst of it with impunity. It was easily dispelled; any great noise, such as the sounding of horns, the discharging of guns, or the like, at once repelled it. It moved only by night; and appeared at times, but less frequently, the following summer; after which this phenomenon ceased. It may possibly have arisen, as the editor of Camden conjectures, from a local casualty, such as the fall of a flight of locusts in that spot, as really was the case in the sea near Aberdaron; which growing corrupt, might, by the blowing of the wind for a certain period from one point, direct the pest to a particular spot, while other places less remote might, for the same reason, have escaped the dreadful effects. Motiffet gives an account of a plague in Lombardy, about the year 591, which arose from the fall of a cloud of locusts, which corrupted the air to such a degree, that eighty thousand men and cattle perished (Pennant, 1810, p372-372).

Based on the single fact that the perceived flame was blue, modern interpreters have concluded, albeit in far more technical terms, that this entire incident was the result of the spontaneous oxidation of diphosphane gas (yes, that would be “swamp gas”), which is frankly not a great deal more sober an explanation than locusts.

The phenomenon occurred over the winter of 1693-1694 and describes the burning of hay ricks and buildings in the vicinity of Tydhin Sion Wyn, a stone house which still stands on the hillside above Morfa Harlech. Observers noted that “’twas a blue weak flame, easily extinguished … that it did not the least harm to any of the men who interposed to save the Hay”. This is a clue to the cause of the fire–a will-o’-the-wisp resulting from the spontaneous oxidation of diphosphane gas produced by decaying organic matter. Diphosphane is a hydride which becomes a vapour at between 20 and 30[degrees] C and can spontaneously combust in air at low concentrations. In this case, the oxidation itself is unlikely to cause combustion but it will probably chemiluminesce in a similar manner to phosphorus vapour undergoing oxidation. However, there is no doubt that combustion did take place and this could be due to methane being ignited by disphosphane oxidation. There are reports of such ignitions. Many years ago the Italian scientist Quirico Filopanti stationed himself by a pile of rotting hemp for several evenings and was rewarded with a bright flame with which he could light a torch. The low coastal plain below Tydhin Sion Wyn would probably be waterlogged and contain much combustible methane, but I suspect that the resulting fires were much closer to the source of the gas than stated, unless they were carried by wind (Pentecost, 2000, p89).

Ockham’s Razor, that tried and true trope of folks who maintain the absolute mundanity of the universe, is generally more useful for elective amputations than it is for exploratory surgery.  Note how clearly stated facts are simply lopped off, and the observations of witnesses largely ignored.  The fires were not as close as people though (despite haystacks igniting).  The dead cattle and dying vegetation that resulted from nightly visits from this will-o-wisp receive no mention, and a complex of strange occurrences is reduced to the spontaneous ignition of swamp gas that happened at a much greater distance than was originally reported.  Over the course of several months.  And was scared away by loud noises. Obviously, it’s just as much of a stretch to suggest that this was some sort of supernatural or alien visitation that generated a lot of heat and irradiated the livestock and grass, but at least that accounts for all the details.

The understanding of parsimony that leads one to the conclusion of swamp gas is closer to the definition offered by Rudolf Arnheim who said, “The principle of parsimony is valid aesthetically in that the artist must not go beyond what is needed for his purpose” than it is to the much lauded principle we hear from scientists and skeptics alike.  If the purpose is to dismiss, all manner of explanations can succinctly convey the dismissal provided you are willing to ignore any additional information as a baroque affectation.  Inexplicability, irreproducibility, and irrationality are a source of great misery to the physicalist and logical positivist, as facts that cannot be stuffed into an acceptable model must be blocked by blinders to avoid the suggestion of mystery and thereby spooking themselves. The poet Milton once said, “To be blind is not miserable; not to be able to bear blindness, that is miserable”.

Neale, J. M. 1818-1866. The Unseen World: Communications With It, Real Or Imaginary, Including Apparitions, Warnings, Haunted Places, Prophecies, Aerial Visions, Astrology, &c., &c. London: J. Burns, 1847.
Pennant, Thomas, 1726-1798. Tours In Wales. London: Printed for Wilkie and Robinson, etc., 1810.
Lister, M.  “Extract of a Letter from Mr. Edward Lhwyd”.  Royal Society (Great Britain). The Philosophical Transactions of the Royal Society of London, From Their Commencement, In 1665, to the Year 1800: Abridged, With Notes And Biographical Illustrations v18. London: Printed by and for C. and R. Baldwin, 1809.
Pentecost, Allan.  “The Last Word.” New Scientist 26 Aug. 2000.