Imperial and US customary measurement systems (42 US gallons, 34.97 imperial gallons or 159.0 litres) used in the oil industry has the dimension of volume and could be replaced by the gallon, cubic metre or litre. The definitions of potential difference (volt), electric current (ampere), electrical resistance (ohm) were defined in terms of metric units, international agreement having been reached at a series of IEC Congress in Chicago between 1881 and 1906 when the electrical industry was in its infancy. At that time the metric system had become established in continental Europe while in the United Kingdom metrication was an active issue. Similarly, the units of
Georg Ohm of a circuit is the product of the strength of the current, and the resistance of that part of the circuit. The book begins with the mathematical background necessary for an understanding of the rest of the work. While his work greatly influenced the theory and applications of current electricity, it was coldly received at that time. Ohm presents his theory as one of contiguous action, a theory which opposed the concept of action at a distance. Ohm believed that the communication of electricity occurred between "contiguous particles" which is the term he himself used. The paper is concerned with