No. 85: Jan-Feb 1993
Window glass with a 7-centimeter hole fitting glass circle believed to have been created by ball lightening.
The majority of these balls entered through closed glass windows. Sometimes the balls penetrated the windows without damaging the glass at all, but in a few cases neat circular holes were somehow melted or punched through the glass. The accompanying photograph illustrates an incident in which lightning (supposed to be ball lightning) surgically excised a coin-like piece of glass.
(Girgor'ev, A.I. et al; "Ball Lightning Penetration into Closed Rooms: 43 Eyewitness Accounts," Journal of Scientific Exploration, 6:261, 1992. Journal address: ERL 306, Stanford University, Stanford, CA 94305-4055.)
Reference. An entire chapter of our catalog Lightning, Auroras is devoted to ball lightning. Ordering information here.