Brewing, saw-milling, boat-building, and the manufacture of biscuits, soap and submarine cables are also carried on.
Actual or projected routes for telegraph cables across the deep sea have also been sounded with extreme accuracy in many cases; but beyond these lines of sounding the vast spaces of the ocean remain unplumbed save for the rare researches of scientific expeditions, such as those of the " Challenger," the " Valdivia," the " Albatross " and the " Scotia."
This formula is important in connexion with the capacity of electric cables, which consist of a cylindrical conductor (a wire) enclosed in a conducting sheath.
Emden is also of importance as the station of the submarine cables connecting Germany with England, North America and Spain.
Telegraph and telephone cables join these ports, but a regular passenger route does not exist owing to the unsuitability of Portpatrick.