He was one of the first scientist on the American continent who made Xray photos of hands, sculls, knees and elbows. He was the first to point to the harmful effects of a long exposure to these rays on human organisms.
In the period 1881-82 he was employed at the Central Telegraph Office in Budapest. Here he began his career as inventor improving the voice amplifier for the telephone receiver, and in February 1882 arrived on the idea of the rotating magnetic field. The first patent, "Com-mutator for dynamo - electric machines", applied to the Patent Office on May 6, 1885 was followed by a series of patents on electric arc lamp regulators. From 1887 to 1890 he applied his wellknown patents on polyphase alternate currents, generators and motors.
From wide field of his researches were alternate currents of high frequencies and their effects. On May 20, 1891, he gave a lecture to the AIEE in New York on the "Experiments with alternate currents of very high frequencies and their application in artificial lighting" In 1890 he also published the results of physiological effects of high-frequency currents.