Puigcerdą is the capital of the comarca of Cerdanya, in the province of Girona, Catalonia, Spain, located at 1,202 metres above the sea, by the river Segre, not far from its start in the French Cerdanya. Population 6,356 (1996).
... device looks confusing at first sight, but is surprisingly simple. It can easily be understood with a little knowledge of gyroscopes. Their striking property is that the ...