Show MODERN THEORY OF THUNDER intense heat of electrical discharge turns vapor into steam and causes loud explosion there have been a great many different theories about the causo cause ot at the lotse wo we call thunder some savage nations chink it Is caused by the clouds knocking together in a storm and making a spark like two pieces ol of flint with a crackling sound at the same time not long ago when electricity first began to be understood many persons believed that the lightning made a hole in the air ad as it passed along and that the rush of air to fill up this vacuum caused the noise eJust just as it Is caused by the air rushing back into the vacuum in a big cannon the more modern theory based on some remarkable experiments with very fluffy cotton that was waa made damp Is that the intense heat of the electrical discharge instantly turns the surrounding vapor of the clouds into steam and causes an ail explosion as aa ws den and fierce as gunpowder it to Is the number and diversity of these explosions that makes the crackling sound we hear when the thunder Is close to us which would not be the case if the cause were tho the air rushing into a single vacuum as that would make only one big bang juet like a cannon |