John Stone Stone (September 24, 1869 – May 20, 1943) was an American mathematician, physicist and inventor. He initially worked in telephone research, followed by influential work developing early radio technology, where he was especially known for improvements in tuning. Despite his often advanced designs, the Stone Telegraph and Telephone Company failed in 1908, and he spent the remainder of his career as an engineering consultant.
Stone was born in Dover (now Manakin) village, in Goochland County, Virginia, the son of Charles Pomeroy Stone, an American Civil War Union general and engineer, and Annie Jeannie [Stone] Stone. From 1870 until 1883, General Stone held the post of Chief of Staff to the khedive of Egypt, and, while growing up in Cairo, John Stone Stone became fluent in Arabic, French, German and Spanish in addition to English. His father tutored him in mathematics, and following the family’s return to the United States, Stone attended Columbia Grammar & Preparatory School in New York City, after which he studied civil engineering for two years at the Columbia University School of Mines, followed by two years at Johns Hopkins University, where he studied mathematics, physics and theoretical and applied electricity.
After completing his education, in 1890 he began working at the American Bell Telephone Co. in Boston, Massachusetts, in the experimental department of its Research and Development Laboratory. While there, drawing on the work of Oliver Heaviside, he made a rigorous mathematical analysis of the company’s development of a long-distance telephone link between New York and Chicago. His later work involved electrical resonance, which he initially investigated for its potential use in an automatic telephone exchange. In 1892, he attempted to wirelessly transmit audio using “high frequency transmissions”. This effort was unsuccessful, but the work proved applicable to the development of “wired wireless” (also known as “carrier current”) transmissions over telephone lines, although his patent application was later ruled to have been anticipated by Major George O. Squier. In 1893, he developed a “common battery” system for telephone use, which provided, from a central location, the electric current needed to operate subscribers’ phones. From 1896 to 1906 he also gave an annual short course of instruction in electrical resonance at the Massachusetts Institute of Technology to graduating classes in physics and electrical engineering.