Kirchoffs major contribution to physics was his experimental discovery and theoretical analysis in 1859 of a fundamental law of electromagnetic radiation. Outstanding among his other contributions was his early work on electrical currents (1845-1849) and on the propagation of electricity in conductors (1857). A master in the mathematical analysis of the phenomena, he insisted on the clear-cut logical formulation of physical concepts and relations, directly based on observation and leading to coherent systems free of hypothetical elements. His teaching had a considerable influence on the development in Germany of a flourishing school of theoretical physics during the first three decades of the twentieth century. He is most well known for Kirchoffs voltage law, which states the sum of the voltage rises and drops around any closed loop in a circuit sums to zero, and Kirchoffs Current Law which states that current into a node is equal to current out of a node in a cicuit.