Electrical cable Electrical cable An electrical cable is an assembly of one or more wires running side by side or bundled, which is used to carry electric current. The term "cable" originally referred to a nautical line of specific length where multiple ropes are combined to produce a strong thick line that was used to anchor large ships. As electric technology developed, people changed from using bare copper wire to using groupings of wires and various sheathing and shackling methods that resembled the mechanical cabling so the term was adopted for electrical wiring. In the 19th century and early 20th century, electrical
Coal measures Coal measures The coal measures is a lithostratigraphical term for the coal-bearing part of the Upper Carboniferous System. The Coal Measures Group consists of the Upper Coal Measures Formation, the Middle Coal Measures Formation and the Lower Coal Measures Formation. The group records the deposition of fluvio-deltaic sediments which consists mainly of clastic rocks (claystones, shales, siltstones, sandstones, conglomerates) interstratified with the beds of coal. In most places, the coal measures are underlain by coarser clastic sequences known as Millstone Grit, of Namurian age. The top of the coal measures may be marked by an unconformity, the overlying rocks being