On 30 July 1891, at the age of 35, Tesla became a naturalized citizen of the United States, and established his South Fifth Avenue laboratory, and later another at 46 E. Houston Street, in New York. He lit electric lamps wirelessly at both locations, demonstrating the potential of wireless power transmission. In the same year, he patented the Tesla coil.
What did Tesla patent in 1891?
the Tesla coil. the Tesla coil Tesla coil