On June 7, 1195, a fiery spinning ball emerged from a dark cloud in the sunny sky close to the London city. An account of this extraordinary moment survives in a chronicle (编年史) between about 1180 and 1199 by Gervase. It would appear that this is the first credible record of ball lightning in England, and much more convincing than the earliest European description, which was believed to be from the 17th century.
Historians discovered the account of what appears to be ball lightning while exploring Gervase's records of natural events in his chronicle, a treasure of historical details giving insights into medieval culture. They dug through hundreds of pages in Latin and came across this sighting. Gervase's records of natural events appear within the historical narrative, often with no opening statement, and the account of ball lightning is sandwiched between the events of the changing of kings at that time.
No attempt is made to explain the "marvellous sign" in the sky seen near London. Readers are left to draw their own conclusions. But Gervase appears to have been a sharp-eyed observer and reporter of celestial (天空的) activity. His fanciful description of ball lightning is remarkably similar to modern reports.
For a long time, ball lightning was regarded with skepticism. Although it is now generally accepted as a genuine phenomenon with thousands of reported sightings, there is still no accepted scientific explanation of its origin. Understanding the phenomenon has been blocked by an inability to reproduce the effect convincingly in the lab and partly because of the variations in eyewitness reports. Whatever the case, centuries later, Gervase's record makes stimulating reading for modern scientists as well as historians.