To imitate thunder, provide a thin sheet of iron; hold it by one
corner between the finger and thumb, and allow it to hang freely by
its own weight. Then shake the hand horizontally, so as to agitate the
corner in a direction at right angles to the surface of the sheet.
Thus you may produce a great variety of sounds, from the deep growl of
distant thunder to those loud claps which rattle in rapid succession
immediately over our heads. The same effect may be produced by sheets
of tinned iron, or tin-plate, and by thin plates of mica; but the sound
is shorter and more acute.
Partial flashes of lightning, aurora borealis, &c., may be beautifully
imitated by taking in a spoon about a dram of the seeds of lycopodium,
and throwing them against a lighted candle, all other light being
excluded from the room.
A similar effect may be produced, by laying some powdered resin on a
piece of paper, and fillipping it with the finger against the flame of
a candle.