Douro, a river, and the largest, of the Spanish Peninsula, which rises in the Cantabrian Mountains; forms for 40 m. the northern boundary of Portugal, and after a course of 500 m. falls into the Atlantic at Oporto; is navigable only where it traverses Portugal.
Definition taken from The Nuttall Encyclopædia, edited by the Reverend James Wood (1907)
Doulton, Sir Henry * Douster-swivel