No abstract

No abstract

A physicist, a biologist and a neuroscientist walk into a bar. What sounds like the beginning of a joke is in fact how the Pint of Science Festival works. This year, from 14 to 16 May, 26 scientists from varying backgrounds walked into bars at three venues across Cape Town to bring us three nights of TED-styled science talks. Stemming from an idea to 'Meet the Researchers' in which UK scientists Dr Michael Motskin and Dr Praveen Paul brought the public to the lab, Pint of Science was born in 2013 when they decided instead to take the lab to the public, in the most quintessential of British meeting places-the pub. Now in its sixth year, Pint of Science is held annually in May across the globe, with more countries joining the festival each year.

W. Fong replies: We feel that nothing can be settled by assertions and counterassertions. We shall be well content to let the merits and demerits of our machine be judged by manufacturers and users.]

The paper begins by summarising the way in which the design of high-voltage (above 1 kV) switchgear has been affected by changes in the constitution of the manufacturing industry, both nationally and internationally, by advances in the knowledge and theory of arcs and circuit breaker operation, and by changing tendencies in service conditions that influence specification, rating and testing requirements. It describes the greatly increased application of circuit breakers and totally enclosed switchgear using sulphur hexafluoride as an arc-quenching medium and insulant, the commercial breakthrough of the vacuum interrupter and the universal acceptance and use of synthetic methods of testing circuit breakers. It then deals with ratings and service requirements, research and the theory of arcs and circuit breakers, standardisation and switchgear testing. It concludes by illustrating, with examples, the current trends in the design of apparatus, especially circuit breakers, and the layout and equipment of switchboards and substations.