Existing comment:
Thunder house
late 18th century
Thunder houses vividly demonstrated the protective effects of grounded rods and were used by Ebenezer Kinnersley in his sensational but educational lectures. A model building was filled with gunpowder and equipped with a lightning rod that could be grounded or ungrounded. Applying a spark to the grounded rod, the charge would pass through the house without harm. But a spark applied to the ungrounded rod would ignite the gunpowder, blow the roof of the house, and flatten the four walls in a fiery explosion.
Ungrounded vs Grounded:
Franklin's experiments demonstrated the importance of grounding a lightning rod. Grounded rods were, in Franklin's words, "protective" devices. Ungrounded rods, on the other hand, were used for studying the characteristics of thunderstorm electricity, in all of its brute and fiery power. |