<Tr> <Td> 1938 </Td> <Td> The 132 kV National Grid became integrated . </Td> </Tr> <Tr> <Td> 1943 </Td> <Td> The Hydro - Electric Development (Scotland) Act 1943 (repealed 1989) </Td> </Tr> <Tr> <Td> 1947 </Td> <Td> The Electricity Act 1947 (repealed 1989). It merged 625 electricity companies to be vested in twelve area electricity boards and the generation and 132 kV National Grid were vested with the British Electricity Authority . </Td> </Tr> <Tr> <Td> 1954 </Td> <Td> The Electricity Reorganisation (Scotland) Act 1954 (repealed 1989) </Td> </Tr>

When did electric lights become common in uk