625. Why do electric storms frequently occur after a duration of dry weather?
Because dry air, being a bad conductor, prevents the opposite electricities from finding their equilibrium.
626. Why is a flash of lightning generally succeeded by heavy rain?
Because the electrical discharge destroys the vescicles of the vapours. If a number of small soap-bubbles floating in the air were suddenly broken by a violent commotion of the atmosphere, the thin films of the bubbles would form drops of water, and fall like rain.
627. Why is an electrical discharge usually followed by a gust of wind?
Because the equilibrium of the atmosphere is disturbed by the heat and velocity of lightning, and the condensation of vapour. Air, therefore, rushes towards those parts where a degree of vacuity or rarefaction has been produced.
The name thunderbolt is applied to an electrical discharge, when the lightning appears to be developed with the greatest intensity around a nucleus, or centre, as though it contained a burning body. But there is, in reality, no such thing as a thunderbolt.