Mix two drachms of the filings of iron, with one ounce of concentrated
spirit of vitriol, in a strong bottle that holds about a quarter of a
pint; stop it close, and in a few minutes shake the bottle; then
taking out the cork, put a lighted candle near its mouth, which should
be a little inclined, and you will soon observe an inflammation arise
from the bottle, attended with a loud explosion.
To guard against the danger of the bottle bursting, the best way would
be to bury it in the ground, and apply the light to the mouth by means
of a taper fastened to the end of a long stick.