Past Forward: The Path of Most Resistance

In 1861 or thereabouts, a British doctor and electrical researcher named William Snow Harris published a slim volume containing three experiments. His goal was to help readers visualize conductivity, resistance, and the powerful effects of lightning. The booklet's illustrations were printed with gold leaf, and when the reader applied a charge to one end of the metal, the current would char a black course along the path of least resistance. The booklet was part of Harris's decades-long crusade to convince the Royal Navy to adopt his lightning rods on wooden ships. This illustration shows a poor seaman who accidentally gets caught in the rigging during a lightning storm. As Harris wrote, absent a lightning rod, the sailor “would be probably destroyed.” Despite successful tests on 11 vessels, including the HMS Beagle (of Darwin fame), the Admiralty resisted adopting Harris's invention for over 20 years.