Temistocle Calzecchi-Onesti

Life & Legacy

Temistocle Calzecchi Onesti (14 December 1853 – 25 November 1922) was an Italian physicist and inventor born in Lapedona, Italy, where his father, Icilio Calzecchi, a medical doctor from nearby Monterubbiano, was temporarily working at the time. His mother, Angela, was the last descendant of the ancient and noble Onesti family. His first name is the Italian version of the Athenian general Themistocles.
Calzecchi demonstrated in experiments in 1884 through 1886 that iron filings contained in an insulating tube will conduct an electric current under the action of an electromagnetic wave. This discovery was the operating principle behind an early radio wave detector device called the coherer, developed about 6–10 years later by Oliver Lodge, Edouard Branly, and Guglielmo Marconi, which was influential in the development of radio.