On October 21, 1638, people were gathering at a church in Widecombe-in-the-Moor, Devon, England, when a violent thunderstorm broke out. Witnesses described an 8ft ball of fire going through the church, throwing large rocks from the walls to the floor, smashing pews and windows and filling the church with smoke and the acrid smell of sulfur. Four people have died and many more have been injured in what has been widely recognized as the first known report of ball lightning in England – so far.
A British historian and retired physicist have found an even earlier credible account of ball lightning in the writings of a 12th-century Benedictine monk, Gervase of Christ Church Cathedral Priory in Canterbury. According to a recent article published in Weather magazine, Gervase of Canterbury recorded in his the Chronicle a “wonderful sign” which “came down near London” on June 7, 1195. The sign was a “fiery globe” emerging from below a dense dark cloud, and it predates the Widecombe-in- the-Moor nearly 450 years old .
“Ball lightning is a rare weather event that is still not understood today,” said co-author Brian Tanner of Durham University (emeritus). “Gervase’s description of a white substance emerging from the dark cloud, falling as a rotating sphere of fire and then having horizontal motion is very similar to historical and contemporary descriptions of ball lightning. If Gervase describes ball lightning , as we believe, then this would be the first account of what is happening in England that has been uncovered so far.
As we have already pointed out, ordinary lightning occurs due to the ionization and dissociation of molecules in the air (a process with the impressive name of “dielectric breakdown”), which occurs during a static electric discharge between clouds and ground. Ball lightning is much rarer, to the point that some have even postulated that it is actually a hallucination rather than a true weather phenomenon. As the name suggests, ball lightning appears as a spherical or spheroidal ball of light, between one centimeter and one meter in size and in various colors such as purple, green, white or orange. Just like normal lightning, ball lightning seems to occur mainly during thunderstorms. Ball lightning can persist for a few seconds and the spheres move horizontally near ground level.
Tanner and Gasper were scouring medieval records for reports of celestial phenomena when they encountered Gervase of Canterbury The Chronicle. Much of the monk’s writings concerned the day-to-day operations of the priory – including a detailed account of the rebuilding of the cathedral choir after a fire in 1174 – as well as disputes with neighboring houses and an Archbishop of Canterbury. But Gervase was also fascinated by natural phenomena like eclipses, floods, famines, earthquakes and ball lightning.
Here is the full story, translated from Latin:
The 7th of the Ides of June , about the sixth hour, a marvelous sign descended near London. For the densest and darkest cloud appeared in the air, growing strongly with the sun shining all around. In the middle of it, pushing from an uncovered opening, like the opening of a windmill, I don’t know what [was the] White color [that] exhausted. The latter, rounded under the black cloud, remained suspended between the Thames and the quarters of the Bishop of Norwich. From there, a sort of fiery globe threw itself into the river; with a spinning motion, it repeatedly fell under the walls of the aforementioned bishop’s house.
But how believable was the monk’s account, given that it was clearly based on a second-hand report? The evidence points to a sober, cautious, and reliable chronicler.
“It reported the dates and times of solar eclipses remarkably accurately and completely,” the authors wrote. The same was true for lunar eclipses. “These are all the more impressive considering that observing partial eclipses was visually difficult in medieval times. In a detailed account of the September 13, 1178 partial eclipse, Gervase accurately describes the rotation of the horns of the partially obscured solar disk towards the downward point, as well as the changing colors near maximum eclipse.”