It was not until 1883 that the Wimshurst machine was more fully reported to the scientific community. During the latter part of the 1800s, the study of electricity was largely considered to be a subfield of physics. It was not until the late 19th century that universities started to offer degrees in electrical engineering. In 1882, Darmstadt University of Technology founded the first chair and the first faculty of electrical engineering worldwide. In the same year, under Professor Charles Cross, the Massachusetts Institute of Technology began offering the first option of Electrical Engineering within a physics department. In 1883, Darmstadt University of Technology and Cornell University introduced the world's first courses of study in electrical engineering and in 1885 the University College London founded the first chair of electrical engineering in the United Kingdom. The University of Missouri subsequently established the first department of electrical engineering in the United States in 1886. During this period commercial use of electricity increased dramatically. Starting in the late 1870s cities started installing large scale electric street lighting systems based on arc lamps. After the development of a practical incandescent lamp for indoor lighting, Thomas Edison switched on the world's first public electric supply utility in 1882, using what was considered a relatively safe 110 volts direct current system to supply customers. Engineering advances in the 1880s, including the invention of the transformer, led to electric utilities starting to adopting alternating current, up until then used primarily in arc lighting systems, as a distribution standard for outdoor and indoor lighting (eventually replacing direct current for such purposes). In the US there was a rivalry, primarily between a Westinghouse AC and the Edison DC system known as the "war of the currents". "By the mid-1890s the four "Maxwell equations" were recognized as the foundation of one of the strongest and most successful theories in all of physics; they had taken their place as companions, even rivals, to Newton's laws of mechanics. The equations were by then also being put to practical use, most dramatically in the emerging new technology of radio communications, but also in the telegraph, telephone, and electric power industries." By the end of the 19th century, figures in the progress of electrical engineering were beginning to emerge. Charles Proteus Steinmetz helped foster the development of alternating current that made possible the expansion of the electric power industry in the United States, formulating