Fizeau–Foucault apparatus unit. At the time, Foucault was working at the Paris Observatory under Urbain le Verrier. It was le Verrier's belief, based on extensive celestial mechanics calculations, that the consensus value for the speed of light was perhaps 4% too high. Technical limitations prevented Foucault from separating mirrors R and M by more than about 20 meters. Despite this limited path length, Foucault was able to measure the displacement of the slit image (less than 1 mm) with considerable accuracy. In addition, unlike the case with Fizeau's experiment (which required gauging the rotation rate of an adjustable-speed toothed wheel), he could
Which? the creation of the Scottish parliament in 1999, in January 2002 Which? established an office in Edinburgh. Which? also works with the European Consumers' Association (BEUC) which brings together over forty consumer organisations from across Europe to represent common consumer interests within the EU institutions. The Consumers' Association has the power under The Enterprise Act 2002 to take action on behalf of consumers, including the ability to bring a super-complaint to the Office of Fair Trading (OFT). Which? is one of eight organisations able to issue a super-complaint. The Consumers' Association was among the first groups granted these new powers.