Aside from the Nile, Tigris and Euphrates, navigable rivers while in the Islamic regions had been unheard of, so transport by sea was essential. Islamic geography and navigational sciences were being very formulated, using a magnetic compass and a rudimentary instrument called a kamal, utilized for celestial navigation and for https://folkmusictradition40371.vidublog.com/32301726/not-known-facts-about-sea-shanties